LOL - that's the right palette.
I've always struggled w/ them because, in the price range I could afford, I didn't trust models w/ too many features and moving parts - these things often just start falling apart after a few weeks. So I usually settled for one w/ arm rests and putting up w/ uncomfortable positions when tracking guitars.
But the armrests do come handy for long sessions - on top of the lower back issues, I've also started having problems w/ my right shoulder/arm recently.
The chair should help.
The other thing I need to take care of is the little shelf on which I place my midi keyboard - due to the keyboard's height, I can't push it under the desk when I'm not using it, meaning that it's always in the way, between me and the desk.
Considering how I suck w/ tools and stuff, this will probably be one heck of a challenge. Or my wife will do it.