This page lists popular parts sources such as AES:
http://www.antiqueradio.org/parts.htm
Tubes are generally cheap and readily available (some picture tubes are an exception). Don't waste money replacing all of the tubes for no reason. Many of the old ones are probably still good.
It's not necessary to replace all of the wires in most old TVs or radios.
If you haven't restored old radios or TVs before, a projection TV is not a sensible beginner's project. Very high voltage that can kill you instantly. This article has some advice about finding a repair person in your area.
http://antiqueradio.org/howfix.htm
Phil Nelson