This seems like a reasonably good niche to go after seeing as how you are part of that niche.
My advice would be to go where these RVers go to hang out online. In other words find a very active forum, register and become part of the community.
Once there, look for threads especially the really hot ones with multiple pages where people are asking for a solution to a problem. A problem indicates an angle where you can target your market.
Also look for what they are already buying and if you're a part of the community you can also ask questions like the one you have about online shopping and receiving goods.
You can find your target community online by doing a
google search for rv + forums.
Jay