I agree with Northbound in that you oughta find an LBS that you are comfortable with and want to support, and have them fit you and order the bike. That way, you can also have them build it up (unless you want to, of course) and make any changes to components that you wish. Usually, bike shops will also throw in free servicing for the first 6 months or so of your purchase. Consequently, you can have them make any adjustments you need as you figure out the idiosyncracies of your bike after riding it for a little while. Plus, it's nice to support a local business--and your relationship with your LBS might become pretty important to you over time.

As for sizing, it seems like with the LHTs, the most important dimension to fit first is your reach, as dictated by the top tube length.

Good luck!