^ Thats a really good idea, I'm surprised there are not more places like that.
As far as good mechanics, 1st Rock 4x4 is pretty good, they installed my lockers and built a set of sliders for cheaper than anyone else in town. They specialize in 4x4 repairs/modifications, but can do pretty much any other mechanic work you want done, cheaper than most places and they take pride in what they do.
For engine work, check out George's Cylinder Heads, they do good work for cheap, but they stay so busy that service can be slow some times, but its worth it because you will save $$$.
Avery's Auto has done some work on my parents vehicles, they seem honest with quick turnaround times and good work.
I've had good experiences with AAMCOs in another state, but never used the one in Tucson (and hopefully will never get the chance, tranny work is expensive