You want a real keyboard? You want the best?
http://pckeyboards.stores.yahoo.net/
The Model-M is where it is at. True buckling-spring technology; solid feel, actual (not simulated) key-click.
BTW - if you have a PS/2 connector on your mobo, and can't afford a brand-new Model-M, you can sometimes find old Model-M keyboards at thrift stores, as well as on Ebay and elsewhere. They are becoming rare, though (mainly because if you want a real Model-M, you want one with the IBM logo!). It probably won't be long before the new version is cheaper than the originals!
Also, given their heft and weight, they can double as a handy weapon in the event of a zombie uprising...
Finally - all the ergonomic keyboards in the world won't help you if you have bad typing "posture" (body, arms, wrists, hands), so look into fixing that as well...
...and if you already have or suspect RSI - get to a doctor.
