Dual LNBs to four receivers?

[badmem]

I'm working in Saudi Arabia and at present I have a single dish, with three LNBs pointed at Arabsat, Hotbird and Nilesat. The LNBs are connected to a DiSEq and one cable runs down to one receiver. I am only watching FTA programs.
I have bought a twin tuner PVR/Receiver. I have been told that I need dual line LNBs to be able to view different channels on the two PVR tuners and to also connect the old receiver.
What other equipment do I need to be able to do this and how is everything connected? Is it a matter of adding another DiSEq, so that LNB1A, LNB2A, LNB3A go to one discq and LNB1B, LNB2B, LNB3B go to the other DiSEq, so that I have two cables running down from the roof? If the two cables connect to the two tuners in the PVR , how do I split the signal to the second and third receivers, so that they can watch different channels independently?

TIA

[lincsat]

Gets a bit complicated with having 3 receivers/4 tuners connected to feeds from 3 satellites.

The twin LNB's and 2 Diseq switches would work for your twin tuner RX - otherwise it's quad LNB's and Multi-switches. I know you can get dual satellite Multi-switches with diseq switching, maybe you could get an 8in/8 out locally and get that to work.