I've been running the F59PHI with the California cars for a number of years and have been happy with the performance and reliability.
The trains sets AZL produced, in general, run <= 4 car trains in the real world and they will definitely fit in an 800mm siding. I'm not aware of AZL ever selling individual cars, only locomotives. That said, the individual Bombardier cars were given out at the Z scale convention in 2012, so about 100 cars are available in the world...somewhere.
In general, unless otherwise specified, it is safe to assume all Z scale rolling stock will operate properly on 195mm curves.