One thing you'll find is that the space Heartland designed for the TV was decided without any regard to the actual dimensions of the TVs in the marketplace. In my '08 2800RLS, the TV cabinet was enclosed which dramatically limited the TV selections. The new design opened the space up, a HUGE improvement, but if you have the old style, you'll find that the facings on the front cabinets hide a good portion of the potential screen area so that 32" unit is a waste.
After lots of research, I followed the Consumer Reports advice and purchased a 26" Vizio LCD. It was cheaper and has 98% of the performance of the top rated units that cost upwards of two times as much. It was a great fit with the entire screen area being visible (my preference, the 32" unit, had the outside 1" on each side hidden behind the cabinet facings). The base on the Vizio is essentially an elliptical metal plate with a black plastic cover.
I agree with previous posters that the back/side/top walls of the area are not strong enough to support the weight of the TV without some significant structural modifications. You can do all this other stuff they mention, but I elected to simply drill two mounting holes through the TV base and the cabinet using flat washers on both ends to keep the bolts from pulling thru either the TV base or the cabinet. (I painted the bolt heads with black gloss paint to make them nearly invisible) MUCH sturdier than using the sides/back/top of the TV space without additional carpentry and structural modifications and you won't have to buy the relatively expensive wall mounting units. BTW, an IMPORTANT note, those wall mount units aren't meant for the dynamic stress of the weight of the TV loading/unloading the arm with natural movement in the travel trailer during transport.
The TV is rock-solid stable. No relatively expensive wall-mount assembly to buy or carpentry/staining work. One electric drill, one bit, two bolts/washers/nuts and a dash of black gloss paint. 15 minutes max. My mounting method is cheap, easy, effective and structurally sound although it is not trendy high-tech.