10' Paipo/Bellyboard Questions

I’m building a 10’ paipo that i would like to surf 6" - 1’ summer slop and surf it from the paddling sweet spot. i currently ride hulls in the 4’-5’8 range and 1/2 plywood boards that are 48x19-24" wide.

any suggestions in bottom, rocker, rail, fin placement?

Just a thought... you might be better off standing on the 10 footer and riding the shorties on your belly?