Again, very sweet.

I'll reiterate what I said in my lost post, although briefly:

Drivetrain - check out old 8 speed Shimano and Middleburn cranks from chainreactioncycles.com

Touchy bits - Raceface

Fork - look around for NOS Marzocchi Marathon SL's, the white ones. This bike needs a white fork. Other more expensive option would be to try the new (white) Marzocchi XC700. It looks like a perfect fit for this bike with adjustable travel between 90 and 130mm.

Wheels - I'd avoid American Classic. I have some, they are OK, not very durable, hubs have very poor seals, but they are light and cheap. They also look cheap, I suspect you don't want that. Go for a custom set with perhaps Hope Pro II hubs, DT Supercomp and either Mavic 717 (regular) or 819 (tubeless) rims. You can bling out a set of wheels like these by going with a colorful hub/nipple combo.

Brakes - personally when I built a bike with discs I'll be likely trying Hope Mini's. They are light, perform well, but are finicky from what I've heard. Best thing about them, they are the hottest looking brakes on the market. Definate OCP points there.