Looks like coffee to me. Oscar is right, there is no way a rambutan will survive in California, I've heard that pulasan are more cold tolerant, but would need a green house. I grow langsat, betel nut palm, salak palm and cacao among the tropicals in my greenhouse, but I doubt any will get large enough to fruit. All of the garcinias I've tried have done fine outside, but these only include Luc's, Cuban Aristata, Achachairu, Imbe, and Paniculata.
If you talk to Richard Reid he has a nice selection of Garcinias doing great outside just east of Del Mar north of San Diego