Being primarily a fingerstyle player (and right now, only owning a nylon string classical as my lone fretted guitar), I've thought about this
a LOT. :icon_biggrin:
- WIDE neck, superwide being the only option, realistically. Nylon strings are usually bigger, so the wider the better in terms of string spacing. After some experimentation, I've discovered I love fatbacks, but one could do a standard thin profile if they wished.
- Likewise, wide bridge. The widest spaced guitar bridge I know of is the vintage hardtail strat (2 7/32"), though one could also buy individual saddles & make it wider. However, the vintage strat bridge makes it very easy to get replacement saddles with piezos.
- +1 on Graphtech Ghost saddles & Acoustiphonic pre-amp. I gotta disagree with Stub, there: not all Piezo ("Pee-ay-Zoh"? "Py-Zoh"?) pickups are created equal, and amplification/signal chain makes a BIG difference. I've heard lots of terrible quacky piezo sounds, but I've heard some that sound quite good. I'd say go to a music store that carries Godin, and try one of their nylons through a good acoustic guitar amp. They use Graphtech, as does Carvin on their NS1 - it's a seriously great pickup.
- Hollow/chambered body (the hollower the better, IMHO) I think the L5S hollow or Thinline Tele would work great. I'm also a fan of the plain top, no pickups route, so that limits the options for top & finish with Warmoth (what with the bridge pickup index hole). But there are plenty of ways around that - aizenx's pickguard looks killer on that top routed body. Or you could get a body elsewhere or build your own that wouldn't have the index hole.
For me, I think I'd say I'd go for a 72 Thinline body, get a nice figured wood pickguard (no holes for anything but volume) from somewhere, rout/dremel out absolutely every bit of wood inside that would be covered by the pickguard (I'd do it
carefully though. :icon_thumright

, then vintage strat bridge, Superwide strat neck, and Graphtech system. I think Walnut body, Koa (or maybe Cedar) pickguard, and Rosewood/Ebony neck.
. . . and as long as I'm dreaming, I'd like a pony. :icon_biggrin:
Dang... I really need my Firebird neck to get here - I'm getting serious GAS!