If you want a public wifi I would suggest http://open-mesh.com/store/. $50 each and the signal can be hopped up to 3 ap's, and all ap's can be centrally managed.
I am looking to add a public wifi system with centralized AP management.
D-Link has this setup
PoE switch $350
PoE AP $90
All of the configuration is done on the switch, and the APs download the SSIDs
and WPA info.
Anyone used these?