this guide might help you

http://bss.lacity.org/UrbanForestry/StreetTreeSelectionGuide.htm

It is really a challenge to find a small tree with roots that won't end up being invasive.

I've resisted putting in new trees in my yard in Los Angeles since I do not want to deal with invasive roots. the previous owner of my property planted very invasive trees and I removed all of them. She had planted ficus trees all around the foundation. the city removed the trees in the parkway since they were diseased and had destroyed the sidewalk and my driveway. every time I go to dig in my yard find new roots. All the trees, trunks, and root balls were removed 10 years ago!

I'd start with your local county extension office (google it for the contact info since you didn't say where in SoCal you are). Advising residents on urban gardening is part of their mission.