One of the best decisions I made about rving was to add solar a few years ago. We love to boondock for several weeks at a time and have a couple of golf cart sixes in series. I added first a single 100 watt Renogy panel and a controller from Amazon and hooked them up. After a two week trip camped in the NF I added another 100 before a second multi-week trip. Two panels worked great except for very cloudy days or shade of a big pine. The next year, I bought another 100 and made a simple gadget for it so that it could sit on the ground and be moved and pointed towards the sun as appropriate. I bought fifty feet of 14 gauge landscape wire, fashioned a couple of connectors and now I can plug that into the system when I get camped and move it about during the day. Except on very cloudy days, my batteries stay above 12.3 volts.
One of the panels I used was a flexible panel and I found it to be just as efficient as the more conventional ones. I have less than $500 total in this whole shebang.
You can get very anal and go nuts about this stuff or just keep it simple and make something that works for you. It ain't rocket science. I bought everything on Amazon.
Paul
