Exotica Rare Fruit nursery in Vista California has had some great reviews. i have never been there. Daves Garden has had some positive reviews for this place. maybe worth some checking out.

CA Tropical Fruit Tree Nursery is a good place in Vista.

Here is a link that might be useful: CA Tropical Fruit Tree Nursery

You should try Mimosa Nursery in E. Los Angeles. They have a huge selection of Tropical Fruit trees. I was there a couple of weeks ago. They had Lychees, Longans, Rose Apple, Wax Jambu, Wampee, Mango, Jakfruit, Caimito, Cherimoya, Atemoya, Sugar Apple, Guava and much more. You have to pay with Cash, no checks or credit card

Here is a link that might be useful: Mimosa Nursery

Ong's in San Diego

Thanks everyone for your recommendations. This is very helpful! I will check out the nurseries online.