The device that you are refering to is a multi-switch. With that type of dish it's integrated into the LNB. If you go with more than 4 recievers you will need a 6x8 multi-switch. You will have to run 4 leads from the LNB to the switch to feed it.
This is CABL.com posting #144339. Tiny Link: cabl.co/mLId