Wireless PCI Cards For Windows Server 2003???

Hi.

Why am I having such a hard time finding wireless PCI cards
for the windows server 2003 OS? Is it a no-no or something to
network my servers using a wireless access point? Its behind
a router. Can somebody please tell me what the best wireless
hardware (ie. router and PCI cards) is for networking a bunch of
windows server 2003 boxes? This is a small network serving a single
web site - not a massive corporation. So, no expensive cisco solutions
needed here.

Thanks.