Had a pretty crippling episode of RSIs in both hands about 12 years ago, but have mostly kept it in check since then.
For pointing devices, I just bring a fullsize mouse with me when I work mobile. I'd suggest Razer Diamondbacks, MS Sidewinders, or even Apple's Mighty Mouse, but those are just what work for my hands comfortably. If you have smaller hands, try a Logitech VX Nano, or if mice in general give you problems and your thumbs are good try a Logitech Trackman Wheel. Crank the sensitivity up so you can work with minimal movements.
For keyboards, I don't have a really good suggestion for mobile. I used a Kinesis split keyboard for a few years while recovering from my initial RSIs and think it helped, but it collects dust now and is kinda bulky to carry around. I also tried a Twiddler (single-handed chording keyboard) which was about the only thing workable when my left hand was completely out, but it sounds like your hands are in better shape than that at least and it didn't work well for me as a long term keyboard replacement. Mainly focus on reducing repetitive tasks by scripting/macros.
IMHO your chair and desk are more likely to cause problems when you're mobile than the devices themselves - pay a lot of attention to how you set up your mobile environment. Slapping a laptop down at a coffee shop on a too-short table and sitting in a "we want the customer to leave in 20 minutes or less" chair isn't going to be good for you. Generally the "temp desks" and leftover office chairs in companies have been just as bad. Empty conference rooms, however, often have better chairs and desks.
Especially watch your wrists and elbows in those cases - keep your wrists from being cramped or at unnatural angles and keep your elbows off hard surfaces (esp. corners). When my RSIs were really bad, I found that rollerblading wrist guards helped tons - they were better padded and kept my hands in better positions than the off-the-shelf medical braces and even looked slightly less gimpy
"The algorithm to do that is extremely nasty. You might want to mug someone with it." -- M. Devine, Computer Science 340