Falbrook isn't too far from Thousand Oaks. I've never visited Orchidanica, but I bought my Vanilla plant from them at a show.
http://www.orchidanica.com/
Also there is the Santa Barbara Orchid estates and you could go to Cal Orchids at the same time if you make a trip to Santa Barbara, as they are about a half block apart. Then there is Daniger Orchids in Northridge, which again I have not visited. Here is a site with adds for two of these places.
http://www.sgvoh.org/Advertisers.html
If you are going to be there for the 3rd Thurday, make a trip to the Arboretum for the San Gabriel Valley Orchid Hobbyists meeting. This was my favorite Society, and they have the absolute best raffle table anywhere. And they usually also have a silent auction.
http://www.sgvoh.org/Monthly_Program.html