I don't know why you can't find a new set that will work in the space you have available, we have sets in the RV and in the S&B that range from 7" to 43". The two in the RV are both HD and we have two Blu-Ray players. Both sets are wired to the BOMB with coax and we have no problems. In our old rig we wanted to show the same movie from one Blu-Ray player so I ran a cable from the front to the bedroom. I had to install a splitter at the player and it required 120vac to operate. No biggy.
Being a little creative is necessary but if you don't want to do the installation there are techs all over who will do it for you. Both the CRT sets in our rig have been removed and one space is just blocked off with a piece of plywood with veneer that matches the cabinets and the other I converted to a storage area and shelf for the Blu-Ray player.