Welcome to the forum and congrats on the new rig!
I can't help with recommending an electronics shop in SoCal. I would tackle that stuff myself, but I'm sure someone else will chime in with a suggestion.
Near the coast, we like Flying Flags in Buelton. It's a great base to visit Santa Barbara and Solvang. Then there's Wine Country RV park in Paso Robles which we like as well.
I'm sure some of our members who live closer to you will chime in with better advice for you.
Best of luck.
Rick, Nancy, Peanut & Lola our Westie Dogs & Bailey the Sheltie.
2007 Itasca Ellipse 40FD