Typically wireless = pcmcia internally, needing the pci to pcmcia bridge setup before it can be used. I.e. - no way to boot. Supposedly there exists a few PCI wireless cards that actually can do PXE booting. No idea what it would take as far as wap setup, but at a minimum you'd need one of these cards and no wifi security. Even then I have doubts. Better off using a wireless bridge and your ethernet port.
However, if someone does track down a wireless PCI NIC and gets it to work reliably a lot of people here would be interested.