Hi llyssy,
I think you have 2 possible paths:
The first is to put a satellite receiver at each TV location and be able to watch different programs on each at the same time. This is how a house would be set up. Looking at the
coax layout for the Sundance, which is probably similar to your Greystone, it looks like there's a single satellite coax run to one TV location, but you may have 4 separate antenna/cable coax runs to each of the TVs. Unfortunately, the signals from the sat dish will not travel to a receiver by way of the antenna/cable wiring. All that to say, if you want 4 receivers, you'll need to run satellite coax to the 3 locations currently not wired for satellite.
The 2nd option is to have a single satellite receiver that has a coax output (not all of them do). There are some people who have had some success modifying the coax lines at the signal booster to allow satellite receiver output to flow "backwards" through the antenna/cable connection to the other TV locations. Someone is likely to jump in with details.
You could also opt for some combination of the two; 2 or 3 satellite receivers with some new coax runs, and the remaining feeds through the antenna/cable wiring.
A lot of people are going with auto-aiming carryout satellite dishes. I think some may feed up to 2 receivers, which would put you into the combination scenario. With Dish programming, the carryouts give you high-def TV. With Directv programming, they're limited to standard def.
It's pretty complicated, but if you study the choices and the equipment options, with some work you can get there.