The Rodriguez Rainier is an excellent bike for your purposes. I purchased the Rod UTB model four years ago and love it even more now than when I first got it. The guys at R+E Cycles do a great job fitting their clients based on body measurements, physical limitations/ailments, their style of riding and goals. Mine, however, is more of a multipurpose, loaded-touring, 26"-wheelbase bike. In spite of that, I used it for completing the entire Super Randonneur series and it also took me successfully over the finish line at last year's PBP.
Have you thought where you're going to carry your gear on the bike -- in the rear or up front? For PBP I went with a front set-up but a steel fork with a special geometry for better handling. After discussing the cons and pros of low Vs. high trail forks, I went with a mid-trail steel fork for a happy medium. The guys at R+E can take care of all those things for you.
