Custom MTB for person 6'10''

I’m looking for some advice for a friend of mine who is in the market for a new mountain bike. I would tell him to go to his LBS, but the problem is he is 6’10’’ tall. Given his height, I’m sure he’ll need a custom frame. Does anybody know a good bike builder for tall people? Thanks.

One word: Zinn.

Titus does great custom, hardtail or full suspension.