There are lots of similar products out there that can do what you want. One of the single biggest issues you may have is the long term support from the company you are dealing with. In this months Sound & Vision, there is a letter about a company who made a good whole-house-audio product that went under. No more support! No help if anything goes wrong!
Now, I personally use Crestron in my home and while I think everyone should have it and it works great in 4-40 zones, it is not inexpensive.
Niles, Sonance, NuVo, etc. all make products that basically are a multi-zone amplifier and some keypads for various rooms. They are very limited in functionality, but they tend to get the job done.
I would keep in mind all the things that you may WANT to do that you haven't thought of yet.
1. What about the master bedroom?
2. Bathroom?
3. Study?
4. Rear Deck?
5. Garage or basement?
I currently have my 2,800 square feet of living space broken into 9 zones and have expandability to 16 zones wired in place right now. Yes, a bit much, but it really allows for separation of the areas when music is wanted. The key is, I could have just setup 3 or 4 zones, and I have WIRES IN PLACE to allow a nice upgrade path.
Every room:
Cable, phone, ethernet, control (for keypad), and ceiling speaker wiring.
Some rooms/areas:
Conduit for future upgrades, dedicated video feeds for video distribution, some additional control for motorized blinds and lighting.
No contractor I have met who is good at building homes has a clue how to properly wire a home for whole house audio and to get the job done right. Even less know how to help you take it to the next level.
What area are you in? Perhaps there are some on these forums that can help line you up with a good A/V Integrator or consultant in your area that may be able to give you some solid direction for a fair price.