When I ordered my Powerbook back then I also bought an Atheros5000 WiFi card on spec as it was hinted here that support for such would be upcoming with some MOS release in the future.

This Cisco Aironet I use was basically plug and play, although both LED (orange for activity, green for status) blinking constantly made me suspect an error at first.

http://www.cisco.com/en/US/prod/collateral/wireless/ps6442/ps4555/ps5818/product_data_sheet09186a00801ebc29.html

Only 54 MBit though.