I have two desktops I'd like to build into a wireless network. What I am wondering is if there are PCI cards that play nicely with the airport extreme N on a PC. I am weighing the options of an N network vs a wired and G network. One issue I'm worried about is having PCI cards that don't work well with the airport. I have not bought anything yet but already have wired routers and switches, as well as an airport express so the second option is pretty much free. My other computers are all new (this year) apple notebooks (MB and MBP) I can get this Dlink Xtreme N Wireless Desktop Adaptor (DWA-552) for a reasonable amount (I'm in Canada)

Also (I know I'm digging here) does anyone think they will release N airtunes/express anytime soon? I want to build airtunes into my network but not slow it down with all the older G hardware.