Here's a simple link for you - http://www.greatschools.net/city/Alpharetta/GA.
It will give you all the information you need and determine if the demographic will support the need you want to fill.
Both cities are great - but different. It boils down to what your needs are; and what lifestyle you want to live.
Visit this website and look up both: http://www.city-data.com/forum/atlanta/12299-ackworth.html
I recently relocated myself and these two websites were invaluable. I can honestly say I chose well for my needs. This is your one opportunity to get it right - and if you can afford it - make as many pre-move visits as is feasible.
It will be well worth your while. All the statistics are a great base - but it can't replace getting out here and feeling the vibe yourself.
Now for the shameless plug: I would love to assist you in your move; I myself have moved my entire life and can maneuver the pitfalls that invariably surface! Just click the link and we can start your journey!