As to your question about PCI vs. PCMCIA, I don't think I understand

I currently have a Linux box as my firewall. It contains two PCI Ethernet cards. One of them goes to the cable modem. The other drops down to an 8-port switch.

I'd like to add wireless to this mixture -- I recently bought a Vaio SRX87, which has built-in 802.11b.

I have considered replacing the Linux box with an off-the-shelf wireless router, much as many other people have. However, I'm just as paranoid as Peter about WEP -- moreover, I'm not particularly bothered about people wardriving my broadband when I'm not otherwise using it -- so I'd prefer to put the AP outside the firewall. The currently-available routers don't seem to allow this.

Since my cable-modem only supports a single host, I need to provide NAT for both the internal network, and whoever's connected to the AP.

I mean that I've got (at least) the following options:

1. Get a PCI/PCMCIA adapter card and plug in an Orinoco card (or similar). My research suggests that Linux can run these in AP mode (as long as they have Prism chipsets).
2. Get another PCI ethernet card, and run it out to a wireless AP.

Does that make it clearer?