When you go with the multi-room setup, each receiver has its own private view of whatever satellites you have setup. While your receiver can only tune one satellite at a time, unless it has dual tuners as Lak7 mentions, the receiver can switch between multiple dishes / satellite locations easily and automatically.
Check the
switching post in the FAQ. There are pretty detailed diagrams of different switching scenarios.
If you have a multi-room capable Glorystar setup and are using a 4 port DiSEQc switch for 97/101 access you can easily add two more satellite locations. You could go with a 123/129 dish, or a 123 dish plus a 3rd dish pointing somewhere else completely. As long as you use dual output LNBFs they can be shared between multiple receivers.
Your two receivers, each with a 4x1 DiSEQc switch, would be able to independently switch between all 4 locations, one at a time, and record or watch programming.
Bear in mind that a two tuner unit needs to be considered as two receivers from cabling perspective. It will take up both ports of a dual output LNBF setup. If you want to go from only 2 receivers to 3 or more you will need a multiswitch setup, which is also listed over in the switching section.
Also some PVR receivers can watch another channel on the same transponder as one that you are recording. I don't know if the Glorystar PVR can do this or not.