Hi Icejon, welcome to Rebreather World.
The woman in the shop was probably more scowling about her dead friend than about rebreathers, but there are a lot of very ignorant people about them, especially in L.A.. Then again, there are a lot of ignorant people in L.A., period.
There are a couple of shops in the general area that support them with gas and sorb, and a few that actually sell them. SSA in Montclair, Hollywood Divers in North Hollywood, Beach City Scuba in Huntington Beach come to mind.
Azimuth instructors shouldn't be hard to find. Doub Ebersole here at Rebreather World (he's in FL, though) trains on the Azimuth. Who did you have in mind?
One thing I find curious: Why did you have to ship the Azimuth to New Jersey?
Divesafe, the US importer is in Las Vegas, Nevada. Met up with Mauricio last time I was there. O2 cleaning, valve service, switching gauge, none of that requires the manufacturer or any special shop, other than someone who's setup and trained to handle O2. SSA in Montclair I can recommend, excellent shop in that respect. Much of the hardware is Mares, so spares shouldn't be a problem in SoCal. Only the OMG bits are hard to come by and very expensive.