Hi Dallas, I read your original question and was about to add my (very low value) 2 cents. I have only made a handful of boards, and I can’t really add much to the excellent advice received from GD, JM and others. Some excellent advice in this thread. I would add an upvote for keeping it as simple as possible for your first build, you MAY find it’s too messy, too expensive, too difficult, or whatever else. I doubt it with the support of the great people here, but it is a possibility so try not to spend too much first time round, you will easily lose that extra 20lbs your carrying, just from your wallet 
I started off doing as the guys have said above, I found a space to work (in shed), used a couple of supports and set about restoring an old board, I figured that might tell me if I had the tools, skills, and desire to go any further. It was one seriously messy nob, I now realise that restoring a very old board is even messier than making a new one, sanding off tons of old glass right back to the foam is neither easy, nor clean! I used a cheap face mask, but quickly found it wasn’t doing me much good so I invested in safety equipment with my first real spend. I still haven’t got the set up I would like, I would ideally want a positive pressure full face mask with air system. I am hoping to get there one day, but for now I am using 3M 6000 mask, and a smaller half face one occasionally. You can get damn cheap masks off ebay from China, but beware of the filters as I have received tons of counterfeit 3M filters which leaves you exposed. I know you’re using epoxy and EPS, so you’re way safer already, but in case you ever use poly stuff, bear the safety stuff firmly in mind. Same goes for spraying any paints, clear coats, etc.
Once I decided I was going to be doing a lot more of it, but not enough to spend any more money than necessary, I found a used tatty old caravan in the newspaper for around $200. It’s small, but cheap. I wanted to contain all the crap and dust in one environment, keeping it away from the family etc. Again that’s not such an issue for you if you stick with EPS, but it is nice having a small place which is insulated as I can control the temperatore and humidity easily (https://www.ebay.co.uk/itm/Digital-Indoor-Temperature-And-Humidity-Meter-Alarm-Clock-LCD-Monitor-White/292798306394?hash=item442c23985a:g:vkUAAOSwtxlb2sFP:rk:2:pf:0), and I can also keep all my tools in one place so the kids don’t decide to use them for digging up worms!
One piece of advice I would give you is to take notes. Every time you do anything, write it down. I got an A4 note book, and every time I mix resin, do any shaping, print any decals, basically every time I do anything I write down what I did. As I recently found out, it’s probably a good idea to READ the fecken notes before doing another board, but that’s just another lesson learned the hard way, which seems to be the fashionable way (I like to think so anyway!)
As others have said you are definitely going in at the deep end. That’s fine, many people told me I was doing the same, and while I appreciated the advice, I ignored some of it because I had certain things I wanted to do and was fairly confident I could do it. I was right to some extent, but wrong about some things. The things I took for granted, assuming they would be “easy”, were often the hardest. Likewise, some of the things I was warned are very difficult, I found really easy. We are all different, and nobody knows your strengths and weaknesses except you, just be honest with yourself and take all advice on board, discarding stuff only if you’re sure you can. Shaping is an example, I find that the easies and most enjoyable part, glassing by far the hardest. But I know other people struggle with shaping but find glassing a breeze. One thing I can say with confidence, there is NOTHING as cool as riding a board you know you construced from scratch! It’s an awesome feeling!
Just a word on the shapes, again probably only repeating the great advice already given by other more experienced people here…
Going from a foamy to a fish sounds way too much of a jump to me. Again you could know better, but generally most people would find that a jump too far. You want to enjoy every stage of your surfing, if you go too adventurous you can struggle and this can really affect your progress. It takes a long time to make a board (as a beginner anyway), so make it one you will definitely enjoy AND progress well on. For my first few boards I didn’t use any templates, I made them by taking a load of measurements off a board I liked, then just shaping by hand and going by eye. It was great fun and very satisfying, but I have made one or two from BlendingCurves templates and that sure cuts down on the time and makes it a lot easier.
I would recommend going for an eggy board as already suggested. My vote would be for something like the poacher - https://www.degree33surfboards.com/collections/funboards-egg/standard-epoxy
I have made a couple of ‘copies’ of those, working purely by eye from youtube videos to get the shape into my head. I had no templates or even a board to measure so I just studied pictures and the basic dimensions, and worked my way into it that way. The results were great (in my view!), two wicked fun boards which surf so easy and look great with some resin colour work to liven them up a bit.
https://snag.gy/PREgXk.jpg
https://snag.gy/0Wo5aH.jpg
https://snag.gy/QeWfxX.jpg
It’s a really forgiving shape, keep it thick for buoyancy, keep the tail quite wide as JM wisely suggested, and just focus on planing easily. Give it some hard tail rails so you can turn sharper than that foamy, and you will be flying and doing way more on your board within a few hours of taking it in the water. My kids loved em so much that my wife wanted one. She was on an 8 foot foamy at the time too, and is a slow learned so she wanted something pretty, something she could cherish, and something she could use EASILY because she was nervous about leaving a foamy. It was her 40th birthday too so I did her a poacher style egg as a birthday board, and she loves it. It’s so cool being able to make exactly what you want. You will see this one is similarly flat, thick, and was 7foot long so a whole foot shorter (which definitely helped her progress, but not too difficult to make it unenjoyable).
https://snag.gy/YjBV5i.jpg
https://snag.gy/FZVEjR.jpg
https://snag.gy/lGjwg7.jpg
Not sure if I have added much for you here, but I definitely agree that you should stick to minimal type size, and take it steady. Besides, you will probably enjoy making the boards so much that you will want a few, so why skip over any chances to make another one for your quiver?! You sound switched on there and ready for the effort it will take, so I am pretty sure you will do a decent job, and I hope you enjoy it as much as I do! I love looking at boards in shops now and spotting all the flaws, now I know how to spot them!
Good luck, have fun, and keep us posted with pics of your progress.
Oh and PS - Not sure if you have looked at Viral-Surf.com - they are in France and ship to the UK in quick time, and for cheap prices. They have some great gear too, especially shaping tools and materials. Maybe check them out if you haven’t already. If it helps, I can get stuff from Seabase here, and I could ship over to you. I occasionally send stuff to my mum down in Alicante so let me know if I can help you get hold of anything.