Bang for buck, those are two of the best bikes out there. The biggest difference between the two is that the Jamis is running Shimano Tiagra STI shifters, while the LHT runs bar end shifters. If you're going to be on the road for awhile, and away from a bike shop, the bar ends are easier to service than STI, and less finicky overall.
The LHT has some nice built in features, such as a third set of mounts for bottle cages, and spare spoke holders. The Jamis does include fenders, and they have a neat system for easily adjusting your stem height, although I've read a few reviews from people that have trouble with the adjustable stem slipping.
My personal preference swings towards the Surly, but no matter which you choose, be prepared to swap out the saddle.