From personal experience, I can recommend LG TVs for rs232 control. Insure when you purchase that the specs list that the serial or rs232 port is for service and control, not just service. Then I bought a USB-to-Serial adapter, and a null modem adapter. then just plug it in. All plug-and-play.
I mounted my 50 and my 32 inch models on the wall. Behind the bracket mounting I have cut in a small ( standard dual-gang wall box at any home depot, lowes, etc ) from this I run power, hdmi, and a USB>Serial cable.
Significant Other approved, as you can see no cables.
As to MDs. I have 2 types. One in a small desktop mini case, and one is an actual Foxconn Nettop appliance. The nettop appliance is mounted directly to the back of the 32 inch TV, and the other MD is in the entertainment center , which is built in the wall beside TV, and looks like any other DVD/BluRay player.
But to get back on topic. I highly recommend LG TVs. Again, verify rs232 is both service, and control. then its plug-n-play.
p.s. more details in my User setup linked below.