Thank you all for your valuable input. I am taking all of these into consideration. I did get fitted on a 51cm 520 today with a fairly raised seat and the bike fitter at my shop said it was pretty much a perfect match, and even got fitted on the LHT which wasn't as great for me. The thing about so many of these bikes that have been mentioned is that I can't find most of them in retail stores near me so that I can see how comfortable they are in real life for my individual body. I would be weary of buying a bike before trying it out, especially for a trip like this. I think I may end up getting the 520. The gentlemen at the store told me that the tires on it are very strong, and that he's heard of many making it cross country on one set of tires on this bike. Can anyone chime in on that by chance? Also, lovely guide big_rider, I'm still working on it!