Cool site. I didn't notice this much selection last year. I just ended buying a Kinesis Advantage 2.
I'm very happy with the advantage 2. I'm curious about boards with smaller keys, more compact layout, or extra keys in the same space.
The advantage 2 gives you easy access to the arrow keys with no loss of access to other keys. Eliminates the whole efficient arrow usage problem, or gives you more keys for commands if you use hjkl.
The advantage 2 is not a be all end all fix for hand / wrist pain. Consider starting a hand/wrist exercise regime if you have pain first. It could help enough to not need to buy a board.