Id just make a 64-68in flatbow that was 1 5/8in at the handle, and holding that width until the last 10in. I almost never put in reflex or recurves, I actually love bows with 1-1.5 in of set as I feel they are easier to shoot, I see no giant preformance gain in adding in recurves or reflex, sure you may get 5 or 6 more fps but I dont feel like it is worth it. The design I stated above is my go to design for just about every bow I build, I might make minor adjustments to compesate for density but that is just about my favorite design. If you want you could heat temper the belly on this bow, that will reduce set and bring the tension and compression forces more into balance.