Having met hundreds of touring cyclists on the road, it seems to me that most of them are traveling heavy, many more use panniers than trailers, and more than half use all four panniers. So if you have no idea what you're going to like, and if you believe in the wisdom of crowds, you might consider a bike that can go loaded.
Comparing the Jamis Aurora Elite with the Raleigh Sojourn, I'll note that both have road-bike gearing. If running heavy, I strongly prefer touring bikes to have mountain bike gearing to get lower gearing. The Raleigh, however, has lower gearing than the Jamis. The Jamis has a lowest gear of 27 gear inches. The Raleigh has a lowest of 24 gear inches. Note that the LHT and the 520 have a lowest gear of 20 gear inches, which I think is just about right. Both are suitable for heavy loads, having 36-spoke wheels, and a steel frame and fork. The Jamis has higher quality derailleurs, but costs more (probably due in part because of that). Both have wide tires (Jamis has 32 and Raleigh has 35--I would personally prefer the 35, but that's not much difference and easily replaced). The Raleigh comes standard with a Brooks B-17 saddle, which I consider a great plus.
Given the two above, I'd probably go with the Raleigh. But I'd rather have a Surly Long Haul Trucker or a Trek 520 instead of either of those two. If you decide to go ultralight, I'd look for a good aluminum road bike with 32-spoke wheels.