Have you considered looking at something like a Fishman Rare Earth pickup? It can be retro-fitted to any acoustic with a standard round soundhole, and can just plug into an audio interface. I have the Fishman Neo Humbucker, which is the cheap version of the Rare Earth, but it still sounds really rather good.
As ever, if you're looking to buy a new acoustic, take yourself off to your nearest merchant of acoustic instruments, and then simply sit & play as many as you can. Pick the one that sounds and plays the best.
I did that a few years back, and ended up buying a seriously sweet sounding, all wood, acoustic (no piezo or preamp) by a company I'd never heard of (Naga Guitars). Even today, whenever I pick it up, it sounds as sweet as anything, and anyone who's tried it out really rates it.