Looking to do something similar and might go with http://www.ubnt.com/unifi
I wanted to have one wireless network, same SSID, for the entire range of coverage and I wanted WPA2. From what I read, though, only dd-wrt or some custom implementations will allow this since it's not part of some standard yet?
So I, too, am confused as to wtf to do about this. The scenario is a DSL line going to a modem/router, then from there I'd plug in a wireless system. Totally separate from the main business line which is fiber--we keep the "free wireless for employees" on a totally different system out of paranoia.