Sailhack said..KB - your monitors are too low unless you're a midget.

Advice I was given after starting to suffer from back issues was "monitor(s) should be up so that your eyes are level with 1/3rd from the top of the screen.
Got a trackball also and have wondered about buying the razer keypad but not sure if I'd 'get it'?
Low - yes I agree. I am not a midget but I do have the chair as low as it goes, and subscribe to this:
www.lumoback.com/2013/08/upright-or-reclined-neutral-spine/It just feels right to me.
Plus I can then lean forward and see over my monitors at the highway/clouds etc in the distance - very important for eye health (I make sure I educate the bosses on eye health when caught gazing out the window..

).
As for the trackball I find it great for my work, however I did make 2 mods that I couldn't be without. First is 2 packs of blue tack underneath to raise to a 45 degree angle with the trackball high. So my wrists are neutral. Also paper under the blue tack so it can slide on the desk, and a channel in it so I can still pop the ball out to clean the little rollers. Second is using the logitech software to make the 'button 4' or the index finger front button into the same as the wheel click. That way I can be holding that button easily while scrolling on the wheel - ie simultaneous pan & zoom - very important when drafting.
Razer keypad - I wouldn't be without it now. I have moved from Nostromo to Orbweaver about 6 months ago and love it. Nostromo on my home machine now. I have a cheat sheet, which you can see in pic above, but only look at it about once per day maybe. It just takes you away from being a left hand keyboard basher. I have lots of macros set up too so that for instance "save" sets UCS=w, visretain on, layer=0, then saves.
I started with one keymap and went from there, eased into it. I found the transition fairly easy, with the cheat sheet, but it did take some fiddle time to set up. I make that time back every day now though.
details inc my keymaps here
www.augi.com/forums/showthread.php?130491-Nostromo-2011PS despite the health implications I would quit rather than stand 40hrs per week. What it gives to your heart/circulation/fitness it takes in the form of aching legs/feet, hemorrhoids/hernias & general fatigue etc. Ask your local check-out chick

Oh and my chair is not the exact one linked above, but similar. Chairs are something you can't buy online, you really have to go sit in all the contenders.