Solar panels are the easy, quiet version of powering your RV off-grid. As long as you have sun and a decent setup, you are fully self-sustaining. You can go with a kit, or buy parts individually, but in either case it's a good idea to read the other product guides we have for individual parts: solar panels, batteries, charge controllers and cables. If you do buy a kit, make sure it doesn't include what you already have. Eg. if you already have an inverter, get a kit without one. The kits can be easier to get everything right, and usually come with good instructions, but sometimes they cost more than buying all parts individually, and you have less customization options. Most kits don't come with batteries.
The wattage is how much power the panels generate. The higher the wattage, the more power (and larger dimensions) - typically you'll see 100W, 160W and 175W panels, and most people buy several to get their desired amount
Monocrystalline panels are a little more space-efficient and work a bit better in low-lighting, but are also more expensive. Since you're likely limited on space either to store or mount your panels, Mono panels tend to be better
Pure sine produces a power output exactly like in a house. Modified sine is cheaper, but is less efficient and may damage high-end electronics over time. Some electronics won't even work with modified sine inverters