+1 for what Pataneap said. I've toured a lot on trikes--tandem and single--and the Radical bags are great. Handling is in NO WAY adversely affected. I've bombed down hills (curves, too) at over 40 mph just fine, thank you. You do need liners for the Radicals, but with these, you'll be full-on waterproof. Click here: http://www.crazyguyonabike.com/doc/slideshow/?o=1&doc_id=7710&page=7&v=3j
for a photo of my Catrike fully loaded with Radicals. For big and/or steep hills , do make sure you have extra low gearing. The trike in the photo has a Schlumpf Mtn. Drive, which gives me a low about 10 gear inches. I used it at times up the 19% grades required to get to where this photo was taken. Slow for sure but no crazy strain on the knees. If you choose a trailer, a two wheeled model like the Burley Nomad will not adversely affect handling, although it does make a bigger package for turning around, etc. These trailers are quite stable, and I've towed them behind bicycles at speed over 30 mph with confidence. In short, go do it! Touring on trikes is great. The only drawback I can see is that stealth camping is sometimes more complicated, and they are a bit slower overall than bikes. But you can't beat the stability and overall safety. Do some touring and report back.
Trike is a Catrike Expedition with 203mm rotors, short cranks, and the aforementioned Schlumpf Mtn. drive.