Welcome to the forums, Steve.
It's funny, but every forum has it's hot button topics. For some reason, bike racks is one of them here. There really is a lot of good info out there with all kinds of "stories" about what makes one option great and the same option the worst thing you could ever do.
I'm not sure what options your trailer could have come with, but my Chaparral 390 didn't have the Lippert frame mounted rear rack as an option. I suspect it is due to the length. The other Chaparral over 42 ft didn't have the option either. My rear bumper came with 2 stickers on it. One said nothing over 150 lbs and the other said Absolutely NOTHING can be attached to the bumper.
Here is the one that came on the shorter Chappys. It attaches to the frame rails and looks like it would do a pretty good job. I'd call Coachmen or your dealer and see what options they could give.