802.11 a/b/g question for powerbooks

We are installing cisco wireless and besides the airport extreme card is there any other card that is 802.11 a/b/g + leap + cisco compliant. We have cisco wireless card that is 802.11 a/b/g (CB21AG), but there is no client software for that one card except for windows and the other cards before the 802.11 a/b/g had mac os client software for it. Any help with this subject would be great. Thanks, Sunshine