I feel your pain. This is why I still use an old Apple Extended Keyboard (a.k.a.: Enterprise.) I uses good Alps mechanisms and because it was as close as I could get to what I consider the best keyboard for touch typing, the IBM Model M. Both have the same layout without the large return key, so I can transition between my Mac and PCs easily. (I have 4 Model Ms so that I don't have to worry about ever needing to find another one. 🙂 )
In the past, I would have suggested trying to find a Apple Extended Keyboard, but no one makes the ADB-to-USB adapter anymore. If you don't mind getting a Windows keyboard (so that you can use the Windows key as Command, albiet in the wrong place,) Unicomp still makes "buckling spring" keyboards similar to the Model M, and have the Windows key and are USB.
If you really want to have the Command key in the proper place, then my next recommendation would be to find a Apple keyboard from a G5 iMac. They're not bad, but for me, I they feel a little soft. Beyond that, there's the Matias FK302. I haven't tried that one, but if my Apple Extended Keyboard or it's ADB-to-USB adapter ever fails, that's the one I'd try next.
All of these aren't cheap, but as you already know, for a fast typist, a good keyboard is like a crack pipe to an addict. 😀
(edit: I've just been told that the Unicomp Spacesaver M has a Mac layout with the Command and Option keys.)