An FWD auto can be towed on a dolly. Where one gets into trouble is with AWD vehicles, many of those must be trailered. One of the big gripes I read about is where to stow the tow dolly while camped, this is kind of a silly argument as the dolly will remained hooked to the MH, so there is no storing it.
Choosing between electric brakes and surge brakes, we went with surge brakes as we did not want to have to do any wiring to a brake controller.
As for the many choices out there, they are all good, we chose the Master tow dolly because it was on Craig's list and it was the lowest cost of the ones offered. We are the 3rd owners of it and it still works like new.
I am sure others will pipe in with things I have missed. Good Luck on your search.