I tried all manner of keyboards over the years, and in my opinion, none of them solve RSI. I'm now back to a standard qwerty for the same reason as OP - they're just immediately available everywhere.
What did help my no-longer-existent RSI was simple - I don't rest my wrists any more like I was taught in high school typing class (by an instructor that would whack our hands with a ruler if we were caught resting our wrists).
I do have a bit of De Quervain's Tenosynovitis from the mouse, but I'm solving that with one of those hand stretchers that hook to your fingers and provide resistance when opening the hand. 100 reps a day (25x4) and I haven't really felt it in weeks. Turns out that working out the muscles opposite to the ones you think is the key (therapy putty did nothing).