i think i would put maybe 4 inches of nose rocker and have it pretty relaxed and maybe 2 1/2 in the tail. i really kind of eyeball the rocker until i feel it looks right. i have a basic concept in my head and then i start going from there. little by little until i feel that the rocker is just right
keeping the rocker very gradual not having it really pick up through the last little bit of the nose. a longboard and funshapes have a more more relaxed rocker compared to that of a shortboard. you really have to ask yourself what kind of waves i am going to be ridding. a board with a little more nose rocker will perles , or what ever the word is when the nose digs. also a board with a little more tail rocker will catch waves a little bit easier.
when deciding nose and tail rocker theres about 10,000 things to consider. a lot of times i look at boards that are comporable to what i am building and really go from there
heres a comparison between one of my favourite performance 8’ to the dimensions you mentioned …
because mine was a comp 8’ , it had to be 15" wide at the 12" mark at nose so i was bound by nose width …
your nose looks sweet , but i would be inclined to put some more outline curve in the tail if you want it to hook in the pocket , go 3 fins as well …
in 4 to 8’ waves you should have plenty of punch , plus if your riding on the tail you can lift the nose out of the water so it doesnt get in the way , so a healthy nose lift will help …
run out of time for more details even tho i could elaborate way more …