I had a custom bumper fabricated for the rear of a 2970RL with generators and a receiver fore the Kuat Transfer. We do carry fairly expensive bikes with a cover over them at all times. Note: Trailer light visibility becomes impaired. We opted for Boogie lights to remedy that. Hauled them cross country in a bad rain and wind storm this year. No issues with the bikes or trailer.

Here are the things I would consider as you choose your options:
1) Weight rating of trailer bumper/ hitch
2) RV approved E-Bike Rack (Heavy wieght as compared to regular bikes and designed to withstand the shaking on a TT)
3) Security of E Bikes
4) Covering E-Bikes (Some have plugs for open battery access areas transport with Battery off) weather and security
5) Visibility to traffic behind you if they can't see your lights its your fault in the eyes of the law. (I believe, but I am not a lawyer)
6) Budget- What can you do yourself or be willing to pay for?


Good Luck and safe travels! The E bikes are a huge fun factor at your destinations.