I'm fairly certain that the only cards they support are cards based on the ORiNOCO/WaveLAN chipset. Any WiFi card will need a driver, and the ORiNOCO drivers are already built in, its impossible to replace them with a driver for any other card. Even if you were to find a 5V, 16 bit, non-CardBus card that somehow managed to work, it'd still be a lot more pain than simply buying a 802.11g WAP.