[Kymmy]

For each tuner you need an LNB, so three tuners you;d need a triple LNB (a quad one is probably cheaper as sky uses them..)

As for the tuner well NO, an LNB converts the signal from somewhere in the region of 10-11Ghz down to a more reasonable figure that can be carried down Co-ax without to much attenuation..(roughly about 900-1100Mhz), the tuners inside of the sat reciever handle the lower signal..