Is there a really good reason not to use ultegra for this bike? I've heard that it's the most durable shimano road groupset, and I really do like STI shifting. Are some parts likely to wear out if I end up on nasty roads or something?

I do agree that the 53/39 ultegra crank isn't exactly ideal (the gearing is just too high). What if I got a triple crank, like a Sugino xd2 or a Race Face Deuce XC, took off the big ring and otherwise used my ultegra? Would that even work?

The LHT is 62cm, so definitely uses 700c wheels. It seems like XT hubs are a clear favorite for people online, and the Mavic A319s are pretty popular too. If no one has any objections, I'll just do that.

Thanks for the advice, everyone – the bike really is starting to come together.