PAMP is best solution for value. You can always buy a nice Audio Matrix and some nice amps for a better sound solution. But will pay more all the way around. 

The AES isn't what you need. it has the same power as the PAMP plus a processor built-in, which you already have. So that would be a waste of money. Plus you can get 3 PAMP's for the price for a single AES.

Having two extra zones that can be used for further expansion or bridging for better sound quality, isn't a bad thing.