Rob, Robmac used 2X 440W ish on his van. I asked a friend who's a
solar installer about them precisely because they looked so cheap, he told me their prices were pretty much the going rate for domestic panels now.
I'm looking at juggling my existing panels around and fitting an additional 500W jobbie on my PVC, can't see any good reason to pay through the nose for smaller MH specific ones. Several members have had domestic panels installed for years without any issues.