Debian Hardware :: Wireless N Card Capable Of "master" Find One?

I'm looking into assembling a debian based router/firewall system. Fortunately there is a great deal of documentation available on this subject, so I am confident the project is viable. I'm a bit stumped regarding a wireless card though, especially since I'd like to use a desktop form factor rather than one of the laptop style slots. At present, I'm going with a mini-itx board that has a couple of wired nics and a pci-e x4 expansion slot (supermicro's x7spa-h). So, I can connect an access point to one of the nics and that's job done. In the interests of having one fewer box to find space for, I'd like to use a pci-e card as a (wireless n) access point. To do this I need one capable of working as a "master", rather than only as a "client".

Google suggested D-link's dwa-556. Linuxwireless.org suggests the D-link DWA-556 uses ath9k. It also thinks the ath9k driver is capable of operating as an access point. Can I take this to mean that the DWA-556 will be usable as an access point? If so, all is well, and I may go forth and find any card that uses a driver marked AP capable. If not, say because it's a hardware limitation, how do I go about finding a card that'll do what I want it to?