So Cal Trailer Tire "go-to"????

Pretty much all local tire shops order their tires from the same one or two local warehouses so it doesn't really matter where you go to purchase. They can "get" whatever tire you want in most cases. Find a place you can develop a good relation with and has fair pricing and service after the sale.

Best thing to do is do your own homework on which tires your looking for. GO into the tire shop with a list of two to three brands/sizes and ask for pricing on them.