We aren't in CA but my wife, daughter and I are just getting into trials riding, and will also be trail riding our trials bikes. To start with I will setup the bikes much like I am seeing here with a light set of hand guards and a simple way to carry extra fuel.
As I get better with trials riding if I start to compete I may get a second trials bike for just that, however I am not sure.
As for bikes, wife has a Gas Gas TXT 125 and loves it, don't have one for the my daughter or I yet as we are still checking out our options. I suspect I will get an 80 for my daughter, and looking at a Gas Gas TXT 250/280 or maybe a 4RT for myself.
Best of luck to you! when I get our bikes and have them all setup I will post up pictures and a description of our setups.