I betcha one of the main problems with getting a TV transmitter with any kind of decent power is due to FCC regulations that prohibit any sort of real power lest you cause interference within your area.

Seeing as how you'd need to have your TV on whatever channel you're broadcasting on why not just use a VCR and hide it and the cable somewhere? Use a 75ohm to 300ohm adapter to connect the coaxial cable to the screw terminals on the TV. Cheap and easy, just like my dates!

Anthony