If you type ten-fingered, get an ergonomic keyboard.

Well, try one out, but I don't think they're automatically better.

I type ten-fingered on a flat keyboard (though an IBM model M buckling spring type) and my brief experiences with the "ergonomic" keyboards led me to abandon them. On the other hand, my job is not data entry :-)

Speaking about RSI, I find that what's important is to keep one's wrists elevated about the keyboard. My wrist rests are about two inches high.