I will echo what everyone else said, the LHT is a fantastic touring bike right out of the box. If you are fairly picky as far as what parts you like or just want a fun project and have a little extra cash, there is nothing like building a bike piece by piece. If you go that route and are trying to decide where to splurge, get as nice of wheels as you can, XT hubs are very nice but Phils, Kings, DT's are all even better.

For racks, the Surly racks are damn fine, Old Man Mountain also makes some fantastic yet lighter racks as well.