I've considered similar things in the past and never acted on them, other than to play a Godin Acousticaster and a variety of my acoustics with a variety of pickups. I would consider a top without a sound hole, and move the hole to the upper side facing you. It reduces feedback, makes the top stiffer with more surface to resonate, but maintains some acoustic quality to the tone, and you can still play it unplugged quietly. You may have to rewire the pickup to accommodate this, or fashion some sort of drop in design.

My good friend and former student Josh House (www.houseguitars.com) built a narrow body acoustic recently as a live performance guitar for a customer, not around the pickup but around other considerations, and it turned out magnificent. I had the opportunity to play it before it was delivered, and it had way more tone than I anticipated.

It's a great idea Will. I hope it works out for you.

Peace, Mooh.