The RVi would be a good choice. It's small and easy to attach. You will need to have a 12V outlet that is live (if you have to do a battery disconnect) but other than that, it is good to go. We have used ours for a 1+ year now and love it.
Roger & Mary
2017 Winnebago Navion 24V (Sold)
2014 Tiffin Phaeton 36GH (Sold)