It has been years since I bought my panels. I bought from
Northern Arizona Wind & Sun. They were easy to talk to, about as helpful as anyone could be. I called them several times while deciding what I wanted. They had several employees, and at the time a couple were relatively new to solar. They did not hesitate to say they did not have an answer to a given question, and always ask someone else at the store, or found the answer and called me back.
I felt very strongly about tilt panel mounts. The owner said he would sell them to me, but advised against it. I ask why and he responded it is too easy for people to forget and leave them up, resulting an damaged panels and/or roof. He also said before long, I would find that even though it was a gain, most tire of the raising the panels. As it turns out, I made my own mounts, and he was right it did not take long to tire of the process. Maybe in some parts of the country it is worth while, but not for me.
Northern Arizona Wind & Sun is pretty diverse, not specializing in RVs only. They have many solar related products for many applications. There are a lot of self proclaimed experts that read a little, and pass on information that may not be entirely true. What I really liked about Northern Arizona Wind & Sun is their product line is so huge they do not have to sell products using untruths. You want it, they have it and will sell it to you even while advising you against the purchase and explaining why.
Northern Arizona Wind & Sun also has a Forum,
Solar Electric Power Discussion Forum by Northern Arizona Wind & Sun, with pretty good info from the Forum members.
As I said, it has been years since I have purchased from these guys, but I doubt they have changed much, other than for the better,
Wayne