If you were satisfied with the Jensen before it took a dump, you may want to check for a blown fuse or shorted wire. You will have to do that anyway if installing a new head unit. Could save a few bucks.
The head units that come in RVs are referred to as "double din" head units. Double din means they are typically twice the height of a normal stereo radio. The normal size of the screen is 7" diagonal measure in an RV. Some newer rigs may have larger screens. They are available with/without GPS. If you want the GPS to be very detailed in locating campgrounds, or something camping specific, you may choose to use a stand alone GPS and have a basic head unit.
There are a ton of double din head units on the market. The vast majority are made in China. Read the descriptions carefully as it is very easy to overlook the details. This is an example of one Pioneer head unit without GPS and the second one with GPS:
https://www.amazon.com/Pioneer-AVH-X...din+car+stereo
https://www.amazon.com/Pioneer-AVIC-...ith+navigation
We have two Pioneer head units with GPS, one in a 4-yr old Silverado and one installed a year ago in a Jeep Liberty. In our experience, neither holds a candle to our several year old Garmin stand alone GPS. Both head units work very well for the rear view cameras.
Neither head unit was difficult to install. The wires are coded and labeled. The directions are not bad.
For the Jensen head unit, look in your RV manuals package for 2 rigid formed wires about 6" long. They should be with the Jensen radio manual. They may be in the glove box. These are the "tools" that slide in between each radio side and the housing box. They slide in to release the catch on either side. Some owners have uses a very thin knife on each side. When we got our camper, we had no idea what those formed wires were for and threw them away. We found they were available on live "Jensen head unit removal tool".