They do make 2 channel multi room receivers that will handle this. The problem is that you want to use your parasound preamp.
Here is what I would do:
Buy a Yamaha, Denon or Onkyo multi room receiver.
Use the Parasound as a source as well as any other sources you may wish.
The multi-room receiver can usually send different signals to 2 or 3 rooms.
In each room you will want an IR repeater and probably a volume control. Niles works great. My Denon actually came with 2 remotes for this purpose.
You will now maintain the quality system in Zone 1 but will be able to merge it with Zone 2 if you like. Check Crutchfield for ideas.
I have a Denon 3 zone with amps an IR repeaters in zones all over my house. Adding bluetooth was great. My phone plays wireless in any room I wish.