Best Wireless Card for iMac G3?


I need to get a wireless card for my iMac G3 (Graphite) and was wondering if someone could like me know what would be best. Is there anyway that I could install one inside of the iMac or do I need to go with an external USB one?
It looks like I can just use a regular Apple wireless card which is 802.11b. Do I need to get an installation adapter to use it?

Is this pretty good or is there anyway that I could use 802.11g (or does this iMac not support this technology even with a Linksys card)?
Thanks! Even though it's easier than the AirPort card, do you think it's better/faster? The thing that's nice about the AirPort card is that there's less stuff that needs to be on the desk.