Great place for Paella ??
In case anyone really cares at this point, 10 months later, La espanola in Harbor City will make paella for parties. They import meats from Spain and make sausages as well. They will make seafood, chicken without much lead time. Juana, the owner, is from Valencia. They will also make rabbit paella with advance notice. I don't know about rana/caracol paella or vegetarian paella but you can talk to her. They're listed. ANd this time of year (xmas time) they have a huge selection of imported sweets like Pan de Cadiz and cookies from Spain. Cheap manchego cheese, jamon serrano, imported and their own, and REAL horchata DE CHUFAS, imported (real horchata ain't rice or almonds but made from rhizomes on yellow sedge, kindalike water chestnuts, sweet and milky but non-dairy).
The best place I know of for authentic Paella is Black Sheep Bistro in Old Town Tustin (4th and El Camino Real). You have to call ahead for the paella. I spent my early childhood in Spain, and trust me, this is the real thing. They also offer great cooking classes, and one is the Paella.
Kil--this may not be the kind of advice you're looking for, but (as regulars here know) paella is kind of a religion for me.
Spanish immigrants are almost as avid about preserving their culture as the Brits (there are actually LOTS of similarities between the English and the Spanish). So just as it's fairly easy to find an authentic British pub or two (and a store with Malteasers and other such UK candies...and a place to go for tea) in any major metropolitan area, there are, in most big cities, Spanish Cultural Institutes or clubs where immigrants celebrate holidays, dance, and...often....cook.
If you want a serious paella (as opposed to the rice with stuff that passes for paella in restaurants in America--and, indeed, most restaurants in spain!), you've got to infiltrate these places (they almost never admit outsiders as a general rule). That's the hardcore chowhoundish strategy. Now, if you just want to have a really good version of "rice-with-stuff", I'm sure you'll get some tips from the regulars (I don't know LA enough to help on this one).
If you want to try the infiltration route, let me know and we can work together on this!