I used wheelbuilder.com. They aren't cheap, but they seem to get high marks from most people. They mostly do internet sales, but you can go by the place as well. Maybe stop by on your way to the base of Mt Baldy

A while back I found some dead link on their website with a black-friday type deal that was in-stock, but that had long since died (I had no idea it was months expired) and placed an order. The next day I had a voicemail saying they weren't even sure how I ordered that special as they'd long since sold out months before. They ended up honoring the price and offered me an even better wheel (since they didn't have the cheaper one I ordered). I was impressed, and I'll use them again next time I need a nice wheel built.