hi zigmyser,
My keboard is flat, up is worse, and I recently bought a roll-up keyboard which is completely flat, but am getting used to it when I'm not working to a deadline, and it is very different - will get there in the end.
I have a high back chair with a pillow behind me. It's mainly the hand on the mouse that acts up, but I fractured my little finger on my left hand in December, and now it hurts less if I semi-immobilise it when I type.
I don't take frequent breaks, just to make tea or go to the loo. A deadline is a deadline, and one has to meet it! (I work for myself)
A warm towel is wonderful for aching neck and shoulders, by the way!
Lynda