Try Jeans Flight Training or what was Anglo American Aviation at Gillespie.
Or if you want to pay for the honor to instruct try Plus one at Montgomery Field although it's a bit of an old boys club so it may not be for everyone. (they charge there instructors a monthly Membership)
Anglo has a couple of great instructors with a good sense of humor they would be my second choice after Jeans.
I've rented from a Plus One a couple times. What type of challenges would the "old boys club" pose? How difficult would it be to get a decent schedule there? I noticed some of the instructors hanging out and hitting up walk-ins?
The old boys club seems to keep the training between themselves rather than letting others in on the "gig". I don't think there is too much work there if I'm honest unless you are able to market yourself well. If I remember correctly they also require quite a lot of Dual Given before your allowed to be a CFI member.
I might be a bit miffed I had a run in with there Gillespie Ops Officer when I was there and soon afterwards found myself in trouble everywhere and eventually forced out, thats where the old boys club comes in.