The terminology of Mac "Wi-Fi" has confused me.

Hi all,
A little background first so you know what's going on.
I have a home network which uses a US Robotics 9106 wireless router.
Connected to the router, either wired or wireless, there are 2 desktop Windows PCs, a Laptop and a Tablet PC. There is a pci card, a pcmcia card, a USB dongle and an ethernet cable all supplying the computers with an Internet connection in their own way. They all connect to the internet and run like a dream. In other words, I have no issues whatsoever with the way it is all set up.
Now the tricky bit.
I want to kick one of the desktops into touch and put a G3 PowerMac (B&W) in its place. At the moment, the PowerMac has no method of connecting wirelessly installed. It is also only running OS 9.2.1 but I have more RAM and Tiger on order.
Anyway, after reading as much as I can find about wi-fi and Macs, I'm still confused. It looks to me as though "Airport Base station" is Mac speak for "Router" but does it have to be an Airport gizmo in the Mac or will any pci wi-fi card do the job?
What I'm hoping to do is take the pci card out of the windows desktop and slot it into the Mac but that is probably too much to ask for, lol
Also, does anyone know of a difinitive list of wireless gizmos that WILL work with a PowerMac and a NON-Apple router?
Ta muchly and sorry for the long post.
Steve

Most of them are not cheap but here is a PCI WiFi card that will work in your B&W G3.

http://www.macwireless.com/html/products/11g_11b_cards/11gPCI.php

That is all you need.

Thanks for the reply. As you say, it isn't cheap but it's an option.
The thing is WHY can't any old pci wi-fi card be used? The main thing about these Airport comp cards seems to be that "No software required 'cos it works from drivers in OSX"
But what if you have drivers for OSX that you can install yourself ?
I ain't saying I've got such drivers to hand, I'm just off on a "What if" journey, lol

WEll you kinda answered it. There are no "drivers" to support the wireless cards from a pc. Kinda like the video card situation. There are only certain ones available.