A friend of my boss (who's house by te way I have recently automatized with mp3 audio all over

) owns a building with 4 elevators.
He wants to put a kind of kiosk (flat screens showing advertisements in a loop). He asked me how to do this, so I sent to him some links about all the installations done here.
Now he wants me to take the project for him, and I ask all of you how do you think this can be achieved more practically.
My first toguht was NTSC Flat panels accepting video signal from cheap tuners or RF transmitter/receiver, but maybe that would be too harsh on quality.
I think VGA displays are too expensive, and would require a PC with every display, so more cost. Also he wants the 4 displays showing the same signal. What would you suggest? Thanks.