Some responses to things in this thread:
32 spokes will probably be enough. With nice hubs and nice rims like you are using, you’ll be able to get the tension very even, and they’ll probably stay that way, especially with a little spoke prep. Or you can use blue loctite.
I fucking hate aluminum nipples. They can’t be built up to good, high tension, and once they’ve been on the bike for a year or so, they strip as soon as you go to true your fucking wheel. I refuse to build wheels with aluminum nipples. Any time anyone asks me if they should build with aluminum nipples, I try to talk them out of it. Having a weaker wheel that will probably need several new nipples in a year and a half is not worth the 40g weight savings. I’m sure I would be less strict about this if I were getting paid to build wheels, though.
I honestly don’t think that straight-gauge spokes build up significantly weaker than double-butted. In theory, yes, but in practice, in the direction that they are stronger (compression, basically), wheels are really fucking strong anyway, if they’re built with even tension. Straight-gauge spokes are stiffer laterally, though. For a given tension, the spokes respond significantly less to side-loads. This is important when I’m riding with heavy panniers. This is really noticeable with 700c wheels, to me, at least.
I also like the way wheels feel when built to high tension with straight-gauge spokes. Bearing in mind that it’s been almost a year since I read his book, I recall Jobst Brandt saying that it’s an acoustical property. The rim and spokes resonate well, or something like that. I buy that, because that’s what it feels like, and to me, that’s what good wheels feel like. It’s hard to describe, but it’s there.
I’m not going to deny that butted spokes build theoretically stronger wheels, all other things being equal. But they almost never are. As far as I know, all of the wheels I’ve built for myself and for customers are still being ridden daily and are still reasonably true. Unless the customer made a special request, I generally used whichever spokes we had in stock in the right length that day, butted or straight.
Oh, and loose ball bearing hubs are the shit. Does Shimano use different seals on the track hubs than the other hubs? If so, tha’s too bad, because even their road hubs are sealed better than most cartridge bearing mtb hubs.