Great ideas.
I have the same model and year too

Love it.
Just recently I mounted a 13" lcd tv in place of the seating area light on the cabinets on the kitchen side of the trailer. Managed to run cable inside the wall but still have the dvd and power cables on the outside. I'm thinking of running it off the 12vdc as that's what it's power supply puts out but am worried that I might fry it if it can't handle the voltage range one gets when using batteries. The tv is mounted using one of the brackets designed for mounting tvs and is very secure. Negative is that it's only viewable from the seating area. Positive, I can remove it and put the light back in and not have any extra holes.
My trailer came with a stereo and dvd player built in, both dc. For music what I do is use my ipod and an fm transmitter which allows me to listen to it in the car when travelling and the trailer when parked, or use headphones when outside.
The antenna mentioned sounds like a good option, something I've been looking for too.
One thing to note, I had the manufacturer install a hot water heater last year, silly but I really missed hot water at my finger tips, at the same time they put in taps and upgraded the pump as they said the pump that just works the toilet wasn't powerfull enough for the taps too. Might be good enough for just cold water though, certainly would be better than that silly hand pump.
Cheers,
Steve