I did the same as you... gravel pad is perfect for an RV. It drains well, its easy to enlarge and reduce as camper size changes. Its a relatively easy DIY project and the cheapest option besides parking on grass.
In terms of the cover, I find them to be a pain in the neck. I won't use one. My father in law got started camping 2 years ago and bought a new trailer and cover. He uses the cover in the winter, but found it is a lot of trouble during the summer months.
When I purchase my new RV next spring, I plan on buying a metal carport. So much easier to just back underneath the cover. Its a little more money, but a lot easier and less likely to rip.
FYI, when we get the new camper, I plan on pouring concrete pats right where the tires sit. I'll make the pads level side to side so we can pre-cool the fridge before we leave. I figure a couple bags of concrete, some rebar and some 2x4 framing shouldn't be too expensive, permanent or difficult.
