I think it will all depend on what the amp can do. There is a difference between commercial multi zone amps and residential multi zone amps. Usually when a commercial system calls itself multi-zone it means multichannel amp. In other words say 5 zones with independent volume controls but listening to the same thing. It doesn't mean you can listen to 5 different thing in five different rooms which is probably what you want to do. I may be wrong my experience is at least a decade out of date and things may have moved on; can you give us a link to the amp you have chosen? One plus of these PA amps is they often have intercom hook ups for whole house messaging type applications but they are normally not remote controlled and can only be adjusted form the amp itself. Fully functioning multi room amps seem very expensive for some reason. I am still researching but think I will go for a more straight forward setup using a few amps with zone a/b switches. Its not as good but you can link interconnecting rooms OK (bedroom/ensuite kitchen/lounge etc). Also if you use squeezebox you can still sync everything.
Hope that helps,
Simon