Hi mate , I have two big panels in top of the Motorhome which go through a solar splitter box so it charges the battery's and supply power, the panels them selfs just trickle charge the battery's but would suggest it would be better if you got a split charge from your engine when it's run to charge the battery up and you get the biggest amp her leasure battery you can get as cheap and cheerful don't last if you can afford it get a gel one far better and last longer.
For general use id a 12v light and a radio they will last a good few hrs easy depends on what or how much you use them, led build fitting best for your lights , radio try get a simple easy use which requires little energy as normal car radio will drain them quick.
Fir example I had two 14x14 inch panels hock up to the solar splitter then to a battery inside my mother log cabin which ran a 12v car heater during the night to stop the water inside freezing up in the pots containing her flowers(she's a florist works from home) it worked really well.
I'm now in process of removing them and going to use them to run the wee heater and to trickle charge the battery's in my garage and to run a pir 12v security light .
As fir damage its glass so basically any and all on a Landy required! If you can afford it the suitcase type would be good to wire up once your stopped but not fitted always to risky on a Landy .
But I stick to my original answer get a split charge unit fir the Landy so while driving it gets charged up all the time and ready fir use plus it's cheaper.
Hth
Oh if you want to see the solar set up, come by your most welcome can show you both set up .
John
