Check out Kobalt's air tools. I have been using a 1/2" impact from them for a couple years now and it is a beast. It couldn't be beat for the price and torque....think I paid $70 for 600 ft/lbs. Don't waste your time with the smaller 250-300 ft/lb impacts. you'll find yourself doing as much work by hand as with the impact.
How do you like the Gladiator system? I am considering outfitting the new garage with Gladiator (or the like) components. My wife is insisting that I have a nicer looking garage in the new house. I told her that it is not going to come cheap at all, but I respect her stance on the matter
I've always built my own shelves and work benches, but she doesn't want to see anything more than bikes and a floor jack.