Humm, 27" might be a tad large for that space. Think we had a 21 or 22" in our 26BH.
There is a backer board to mount it to. The screws I used went thru a little. Put little plastic dimples over the ends so wouldn't hurt anyone in a bunk. There are no 2 x 4's in trailer walls. You can easily measure the thickness of the wall. The weight should not be a problem.
2012 Toyota Tundra 5.7 Litre DoubleCab
6 speed, 4.30 Limited Slip, Tow Package
2013 Jayco White Hawk 27DSRL
2010 Jayco JayFlight 26BH sold
Yamaha EF2000is Generators (2)
1996 Honda CB750 Nighthawk