Hacker News Reader

While I love typematrix keyboards, and I also have to say that their tech support is really outstanding, the build quality is pretty weak and my experience with those keyboards is that they are not very robust. Still, the typing experience is awesome and they map particularly well on Linux.

tip: while they can be expensive, a coupon search on google will relax the price a little bit.

I moved to keyboards from the first link, the Tenkeyless ones, for exactly the same problem that the OP has. That plus getting my mouse at exactly the same height, so my forearm doesn't move up or down when moving between them, did the trick.

One of the best $100 I've ever spent.

I like the layout of the type matrix, thanks for the tip. The directionals might be more useful to you closer to the resting position. Also, the separation between left and right hand keys probably helps with overextending as well.