In any major city, you're going to find Sysco Foods and U.S Foodservice. They're huge comapnies that will have 99% of the stuff you'll need to open/operate a restaurant. They have minimum orders and other terms. You could also try Restaurant Depot. There is one in Phoenix and they also have almost everything you may need. All you need to get a membership is a copy of your tax I.D. #. They have competitive prices and usually better prices than the other guys. The only catch is you go and shop for it yourself. Like a grocery store.
18.5" WSM, 22.5" Weber Kettle, Weber Smokey Joe