Most of the distributors require a minimum order ($500 or 600 if you want delivery, less if you're picking up at their dock). If you want just the core meat products you'll use, a smaller meat specialist like K&M Meat in Vernon or Newport Meats in Irvine might be ok for you.
If you want paper, foil, packaging, cleaners, utensils, Cambro, bread, condiments, and so on, then a broadliner like Sysco, US Food (La Mirada), Goldberg & Solovy (Vernon) will be better. The main advantage of going w/ a broadliner is they'll carry a wider, deeper selection of name brand goods than Restaurant Depot. Otherwise, you can get the job done at RD.