1 - Ever seen the steel shelf supports that are used to make a flip up section at the end of a counter or other location? Build a bigger version of that and mount some panels on it so that they can be flipped up once on site. Put them at roof height, and buy panels big enough that they will shade the side windows on the camper when folded up (horizontal). Shouldn't stick out more than 3" when folded down (thickness of a panel plus 1" square steel tubing plus some fudge factor) off the sides of the vehicle, which is less than the additional space a side view mirror takes up.
Use the alternator to charge while driving via a DC to DC charger. Get on site, and fold up your window shade awnings/solar panels for power. Leaves the roof open for other uses too such as a roof top platform, carrying some gear, more solar panels, vents, etc.
Something I am thinking about for my next build anyway.
2 - I find with some measurement and planning, you can pick up fairly good sized panels very inexpensively if you simply search on craigslist. Usually it is someone who did a house and has some left over, or it is a solar company that over ordered. I bought my 320 watt single panel for $220 two years ago. Just looked yesterday and found 2x ads. 1 for 305 watt panels @ $180 each, and another for 310 watt panels @ $140 each. Win for you, win for the guy who ordered/paid for too may panels for his house, etc. FWIW.