may as well put my experience's with 24" stuff in here.
rims
atomlab aircorp - very strong rim, reasonable weight (650g-ish see somewhere above) but the sidewalls need the black coating grinded or filed off, as soon as some water gets on it, it goes slick. still a good rim though!
dmr deevee - cheap, seem to be strong so far. no trouble with them what so ever. got mine from wiggle for £16
+ p&p
Tires
Intense FRO DH - the daddy of tires so far, very very grippy. really thick stiff sidewalls, running about 15 -20 psi in the back and no punctures and i have twatted it a few times. the tread is fairly soft but lasting fairly well i would say about probably get about 2 1/2 to 3 months use out of it. its a thin 2.35 that a thinner that the irc kujo dh. fairly heavy but it confidence inspiring tire!
IRC Kujo DH - good tire, long lasting, hard tread, but offers good grip. lasted about 6 months before the sidewalls start to get really thin and would then puncture easily. but overall a very good tire. the 2.35 is plenty wide enough. lighter than the intense
Tioga Comp III 2.1 - hard tread, but last ages, and wards off punctures pretty well. would be a bit better if it had a squarer profile, but good front tire and pretty lightish.
if you are stuck for a tube a 26" one can be used with no problems. but i normally use bog standard rayleigh/halfords 24" and both seem fine.
finding a wheel builder can be hard i went to stif and they wouldn't do it and neither would a another couple of bike shops, but manage to find one that would and was alright.