Coral Oasis in Costa Mesa carries Loc Line. You could probably pick up a cleaning crew from them too.
For the crew, it all comes down to taste. I like a good mix of snails (about 1 per gallon), emerald crabs (maybe 2 for 50gal), and a brittle star. Cleaner or peppermint shrimp also make good additions. A sand-sifting goby (diamond, sleeper, railway) also helps out.
Just be aware that you will end up spending around $150 to pick up a basic crew for your 50gal.