You didn’t ask but I’ll volunteer anyway. It’s common for surfers at varying levels of skill to go through a bunch of different sizes and shapes on the trial and error basis before they figure out what will work for them. There is another way of doing that which doesn’t involve trying to make a selection from whatever a retail shop has in their racks at the moment. And that’s to start with the surfer’s attributes and skill and intended conditions and work backward from there into a design instead of hoping an existing shape will fit whatever the surfer is trying to do. In terms of the retail experience, a shop will always try to make a sale out of the inventory they have in hand - what they want to sell to you as opposed to what you might otherwise choose to buy if you could get your hands on it.
Many of us backyarders got into building our own because we were having a tough time finding what we wanted off the retail racks. I know that’s one reason I got into it.
Maybe I’m missing something but the only difference I see between the 6’6" Experience (the long version of the purple board you posted) and the 6’6" Whiskey Fish is the Experience has a wider nose and tail. (Maybe if he used a round tail instead of the fish tail it would be narrower though.)
The purple board has a different template. The wide point is forward of center which will put more volume under your chest while paddling and a comparatively longer curve behind that wide point to the tail block. Plus, no corners in the tail. That will make for a neutral and consistent feel through the turn, as opposed to the more abrupt (and less predictable) release when the swallow tail (or a squared tail or variation thereof) breaks loose.
You’re big enough that a 6-4 or 6-6 length with your other dimensions would still be easy for you to control. You’ll get a little more float and a little more margin for error for your paddling and transitions, but they’re still small enough for you to duck dive.
Like I said, a round tail will provide a real consistent and nuetral feel in your turns. Not as exciting to ride as a hard corner but markedly more forgiving. No surprises. Which will be a good thing for where you’re at right now. If it matters, the last time I did a 6-6 length for my own use in head-high plus conditions I used a round tail.
About build, big guys with thick board don’t care flex even at high level. In fact many guys “don’t care” flex even if they talked about because shaping microcosme talked about it as “the new improvement” justified “new tech” or to stay “old tech”, blablabla…
Big guys with thick board must care about durability of deck. For eps go with 1.5 to 2lb, you can forgot stringer but ask deep resin saturation of foam and thick lam on deck, at least 16oz of glass, or better a sandwich build for deck.
