Should I buy?

Is your tow vehicle already factory equipped with a 2" hitch receiver? Does it have a round electrical (Bargman) connector? It likely has both of those given the model truck you have, then you would need to get a trailer brake controller if it is not equipped with one from the factory. In my case, I chose the Hopkins InSIGHT Flex-Mount proportional controller. Others choose the Tekonsha Prodigy P3. One that does not require as much installation is the wireless Tekonsha Prodigy RF Wireless. You can see these and more at www.etrailer.com. As for a hitch, you could go with a simple ball hitch (cheap). However, it is good to have a hitch that will give you sway control, either a friction sway bar or something like the Progress Industries E2 which combines weight distribution and sway control and is relatively inexpensive. You could go all the way up to the Cadillac of hitches, the Hensley Cub, which is what I have (got it at a good discount) but it is way overkill for what you would need with that Dodge Ram. Weight distribution is not necessarily needed with an R-Pod, but it does help on those concrete roads where the seams get the truck and trailer porpoising (bouncing up and down). The sway control is not needed in most cases, but it is better to have it and not need it than to need it and not have it.

If you rent a trailer, the company from which you rent it should be able to help with a hitch as well. It may be part of the rental package. You would have to check.

The Oliver and Bigfoot and maybe a very few others are actually insulated to prevent winter freezing, so you can use them all year.  Casitas and rPods are not, they are really 2.5-3 season campers.  You have to winterize them, which is very easy. You can still use them in cold (but not really cold) weather but you can't really use their water systems. So I see you want to spend time in the VA/MD/PA area near the civil war battlefields, that would limit you to say April through October/November.