Multi-Room Audio-Do I really need 6-zone system for 2 or 3 zones

All,
I come to this forum very humbled. Also, understand that it has taken nearly 4 years just to convince my wife to put more than $1k in this room for anything related to audio. I say that as I understand that my product selection may not be considered even middle of the road in quality, but it's better than the nothing I have now. Here is the situation:
1)Builder wired home  for multi-room A/V in 3 zones (formal dining, master b/r, and space between kitchen and keeping room) using Cat-5 and speaker wires to power lines dropped in finished ceiling for pair of in-ceiling speakers in each room
2)My main listening area, the keeping room, is 14w x 10l x 9h. This room is immediately connected to my kitchen, so the entire space of my keeping room and kitchen is 14w x 25l x9h. I plan to put a 5.1 system in the keeping room (currently own Pio 50" 5060, and planning to buy PSB Imagine T-55 towers, B-15 bookshelves, C-60 center, and HSU 10" sub, Episode A4-ICs in the ceilings)
3) I also need a receiver but, that will hinge on the advice anyone can provide me.
My A/V installers have recommended a Pio 5.1 receiver to power the receiver in the main room, PLUS a $1200 Channel Plus MDS-6A-Kit #2 which allows for 6 sources, 6 zones, and 6 key pads to power my other zones.  I need to know if the that kit is overkill given the following:
a) While I have 3 zones for in-ceilings and the volume controls, one of those zones is squarely between the keeping rm (my main rm) and the kitchen, and I really can't imagine that I would truly ever need a separate/distinct zone there since the 5.1 would provide sufficient sound to power the keeping rm and the kitchen. So essentially I think I would ONLY need power to the other 2 zones where I might actually have a different source playing. Am I being limited in my thinking on not feeling I would use the 3rd zone?
b) The chances that I would ever have have more than 2 sources of music playing at the same time in the house is pretty low. At most I would play one source in keeping room and another in the bedroom, or dining room and bedroom, but never all 3.
Like I said, I'm wondering if what they have recommended is overkill, and wondering if I couldn't get away with a nice dual zone 7.1 receiver to power my 5.1, and use the 2nd zone of the receiver to power my 2 zones (master bedroom and dining room). I am also very cost conscious given how long it's taken for me to get my wife to buy into this. I understand that it's tough for an A/V to power more than a pair of speakers in that 7.1 system, so at extreme volumes, this would be suboptimal.
Finally, here are a couple of things that local retailers have thrown out.
Installing impedence controlled volume controllers and do the 7.1. This would prevent the A/V from being pushed too hard if for some reason I decided to run the 5.1 and the 4 speakers in the 2 zones all at the same time. Again, I would never have the volume in the other two rooms high enough to shake the house, or
Using the RTI, RK1 control modules in the 2 zones and a regular 7.1.
Can anyone recommend a receiver and whatever support is needed that would allow me to have background music in the secondary rooms and the 5.1 in the main, without exceeding $1,200 between the receiver and support for whole house audio?
Thanks in advance! :)