Epiphone model do you all think would take to Darkstarrin' the best, as far as cavity routing (if any?) and sound goes?
All depends on what sound you are going for, and what style you like best.
eb0- IIRC, this may be a direct drop in, drilling only for screws.
eb3- Direct drop in at the neck, and some routing done at the body. Routing shouldn't be more than 100 bucks, even cheaper if you find a beginning luthier, or non-luthier woodworker to do the work for you.
-T-Bird Routing would be required, as well as likley some pickup rings, but there's a couple of DS T-Birds around and they reportedly sound great.
-Jack Cassady. Great bass for a darkstar conversion, probably the highest quality bass of the bunch. The arched top requires a bit more finese, and skill, so a qualified luther or talented woodworker would be required. Rodent of the temporarily closed RGB guitar works did a fantastic JC goldtop DS conversion. The process and results are somewhere on TB.
Other basses that work well.
-Any of the old Guild basses with humbuckers are great DS candidates. Asside from the es335 shaped Starfire basses I don't know the exact names, but there's some LP and SG styled basses that are near direct drop in. Probably cheaper than Gibson, and much higher quality than most Epi. Mostly short scale, IIRC.
-Dearmond (Name fender put on Guild styled import guitars when they bought the GUild and Dearmond names). Dearmond Starfire bass is a great candidate
-peavey T-40's and T-45's are direct drop in candidates. All you have to add is a small pickup ring (you can make one out of any thin plastic) to hide the gaps on the sides of the pickup routes.
-"Mudbucker" telebasses are a direct drop-in replacement.
If you have neck you like you could always have a body made for the DS pickups. If requested, Warmoth will route a body for DS's. Darkstars work in any wood, but many folks have reported that Darkstars in Mahogany bodies sound particularly nice.