You need two wires, correct? One for power and another for VGA or RGB? So what do you have, cables running down the celling and then the wall? I'm drywalling the HT room and was thinking of putting the wires underneath wall/celling with a wall insert on celling and wall to hook up the projector and HTPC respectively. But i don't know which wires / wall inserts to use as i don't own a projector yet. Help please!