Bill--
I've had great results with the Renogy 100w bendable panels here:
http://www.renogy-store.com/100watts-bendable-panel-p/rng-100db.htm
These are VERY thin and only 4 lbs. I have two of them and run them at the end of 50 ft of 12 awg cord. This makes it easy to march them out where the sun is so I don't have to camp in the sun!
IMO, it's a waste to nail your panels to the roof of your rv. Not only do you have to camp in the sun (with a bunch of holes in your roof), but your panels will NEVER be properly pointed. If you repo your portable panels once an hour you can easily get 12 hours a day of peak power in the summer.