I just mounted 2 32" LED flat screens in my Kodiak 279RBSL. It had a particle board (I think) backer between paneling for bedroom and living room. I put one TV on either side. I measured the thickness of the wall and used 1/4" lag screws (3/4" long I believe) for the wall mounts. In my case, the pre-drilled holes in the mount were 16" apart (standard stud distance in a house) and my backer board was only about a foot wide. I drilled 2 5/16" holes in the mount about 8 inches apart. It works beautifully.
Bear in mind that new flat screens are really light. My 32" weighs about 12 lbs. Two lag screws even in particle board won't go anywhere. Be sure to "lock" the wall mount..most have the ability to lock the tv in so that it won't fall if there is a bounce. The key is to find a wall mount that is "slimline"... the TV is close to the wall. The further out the TV sits, the more leverage the weight exercises against the screws holding the mount in.
I got both the TV's and mounts at Sams Club. The TV's are Visio and while they only have 720P resolution, the pictures are great.