Have you determined the source of your RSI? That's step one instead of buying a keyboard or anything else. What setup do you have now, and what have you tried changing about it?
The Unicomp's pointing stick tries to solve the "moving hand to mouse" problem, but if it's anything like the Dell pointing stick instead of the Thinkpad one, it might just be annoying to use.
The Tenkeyless reduces the reach to the mouse, which might be a good thing if you don't use the number pad.
If you're used to mashing the keys on a worn-out rubber dome, you'll probably prefer the Unicomp. Bottoming out on the Cherry Blues might be more fatiguing, and trying to lightly tap a switch is kind of tiring if you have to moderate every keystroke.
Neither are alternative layout boards. If your RSI is caused by your wrists being forced together and the rest of your body being forced to compensate, I'd recommend trying out a cheap Microsoft Natural to see if it helps.