I would agree with a few earlier posts that a big part of getting out of a RSI state is going to include a regular stretching/exercise regime for your hands/wrists. Early in my career I started feeling hand/wrist and eye fatigue impacting my performance, and some right shoulder pain/overuse. I swapped my work mouse to the left hand and the right at home, and found distance eye focus exercise and arm/hand stretching made a good regular break. Decades later my eyes/hands/wrists are still fine. Caveat would be that I run/cycle/paddle and probably have a stronger upper body now than I did in my 20's.

I currently type this on a MacBook Pro (likeable keyboard for a laptop) and have a 1988 Model M and a Kinesis Advantage Pro (with the triple action footswitch) on my desk. I've used Microsoft Naturals (which were probably acceptably well made for a year or two), and well, lots of crappy keyboards on various servers, sites and a few generations of (mostly) mac laptops.

The Model M was primary my work keyboard for 15 years. It became the home desktop and gaming keyboard for a decade after that. I am a big guy, I seriously can't explain the type of hammering that this thing has taken over the decades. The keycaps pop off (dishwasher=perfectly clean), allowing easy spill cleaning, and I am convinced I could both defend and attack with it. It brings me great amusement to have a keyboard older than most the people I've gamed with, that works as well as it did when I found it under a pile of old pc's in the 90's (perfectly).

I firmly believe that if your seating/desk position is correct, that a standard keyboard like this can be used 'ergonomically', and the spring action allows for perfectly predictable keytravel->actuation without bottoming out, which seems less stressful than pressing at mush->stop. The fact that it accepts up to 12 simultaneous inputs makes it great for gaming, or crazy emacs macros. I've heard good things about the better model m clones, but .. I think anyone who spends serious time at a keyboard should find/acquire at least one real model M.

The Kinesis Advantage Pro is an excellent keyboard - I bought it to replace the M. The overall build quality seems quite high (expensive, it should be) I like the button feel (damnit model m is better) but *it* is quieter. Obviously the layout takes some getting used to, and with the footswitch might actually work for you. I am still a slower typist with the Kinesis but for some operations it might be faster given all the macro possibilities. I use the pedal for ctrl-alt-shft and have mapped them to macros/other functions. I actually find using this keyboard quite relaxing and still slightly weird some part of me wants a much bigger row of foot switches, and a split level desk with multiple keyboards to 'play'

Other than for the most verbose languages (cobol?) I don't find my typing speed the rate determining factor for coding, so pick something comfortable! I also don't think that keyboards alone can make a significant impact in RSI problems without making certain that the rest of your ergonomic details and posture are correct, and that you get enough variety of exercise and stretching.