Thanks for the input, guys.
Well, I have a specific "dream bass" in mind with somewhat specific specs, so to speak. (say that five times fast).
Pickups: one, maybe two Darkstar pickups. (Mr. Hammon is still making them, I hope.) I don't even want to attempt that kind of major surgery (routing) on a stock bass. Warmoth would do the custom routs for about 40 bucks a pop, I think.
Neck: as close to a Geddy/Ric as possible. If there aren't any aftermarket necks that fit those specs, I guess it'd have to be a custom job. Warmoth says their necks fit the "62 Jazz" specs, and I wish I had a way of finding out how that would feel in my left hand. As it is, every Fender jazz bass I've ever handed was too chunky for my left hand. Although strangely, the MIM P-bass fits pretty good because of the flat fretboard radius. But I'd prefer something closer to a Geddy because of the tight string spacing.
Everything else would just be run-of-the-mill off-the-shelf parts. Those are the two specific criteria I'm gunning for: Darkstar(s) and the slim Geddy/Ric neck.