Are you asking for the pusher that is in your signature and photo, or a 5er, like the forum you posted?
On my 5er, I have one of the built in Honda's. I'm happy with it, but it does burn a lot of propane. I had it installed way back when we bought the trailer in 2002. Only 200 hours on it. When I bought, there was an option to somehow use an outboard boat motor fuel tank. That would have given me longer range and maybe easier to fill, but then you have to worry about the carbs when the generator isn't used often. I guess propane was the right way to go.......