Hi Cathie,
As you probably know … I think very highly of Jeff and the Beducation video series. They are a great resource and he is one of the most knowledgeable people I know in the industry.
The Greater Los Angeles area list is in post #2 here but Flexus is the closest to you and most of them are further away. Berkeley Ergonomics is a wholesale supplier and while they do have a small group of retailers across the country and I think highly of them … the only retailer in Los Angeles that carries them I’m aware of is http://www.ergocomfort.com/ in Irvine.
I’ll take a look around the Hesperia area when I have the chance tomorrow or over the weekend to see if there are any possibilities a little closer to you that may be worth including in your research as well.
Phoenix