I feel your pain. I've been plagued by chronic back spasms since I was 18 and brewing hasn't helped things.
I don't have any cheap McGuyver secrets, but after throwing out my back yet again, I finally splurged on buying a second pump and a second burner so that I can have everything side by side w/o requiring any lifting.
I also bought a small stainless table, with lockable casters, that can hold up to 300 pounds, for pushing around the mash tun (you could also use it for wheeling around your carboy after transfering for fermentation):
http://www.amazon.com/gp/product/B000GWED7I/?tag=skimlinks_replacement-20
It also has a nifty basket for holding ingredients or equipment so that you have whatever you need nearby.
All in, I spent a few hundred dollars, but it beat the alternative of a messed up back or splurging $1k+ on a single tier brewstand.
Best of luck and be sure to report back if you find a good solution.
Edited to add: I brew in my garage near a water source, so a long hose attached to a carbon filter is all I need to get the water into my kettles.