What I built, and why I built it this way.
Same as you I am in SoCal, we but right up against the foot hills of Cleveland National forest. We have coyotes, raccoons, and bobcats among other animals lurking around. This morning looking through the neighborhood FB page one of our neighbors about 3 blocks away has had a bobcat stealing her chickens, from her "secure" coop. Now forgive me if I am being to brass here but if a bobcat got in your coop IMO it is not secure.
I built a 4x8 coop under an over hang off our garage and for the run went to TSC and bought a 5x10 dog kennel plus some panel kits to make a 10x15 run for the girls. We topped it with corrugated steel. Two feet of the bottom is covered in HWC. And I can say so far so good, it has worked for 2 years now, no losses due to predators