I've given up on the idea of a PCI 802.11g card for the Linux server. Driver issues are too annoying and an 802.11g bridge isn't much more expensive anyway. So now the problem becomes finding a good bridge. The Netgear WGE 101 seems like it might do the trick. At around $95 it is also one of the cheaper ones.
The WET54G is the Linksys bridge. Reviews are not very flattering and it is more expensive.
The WGA54G is the Linksys game adapter which doesn't have anything to do with games, of course. It just means it is a single-port bridge and it is a bit cheaper than the WET54G. But unless it was much cheaper than the Netgear I think I'd still prefer the Netgear.
Another option would be to pick up another WRT54G since it can be hacked into acting as a bridge if you turn on WDS support.
And finally there is the D-Link DWL-G810. I have not had good luck with D-Link gear in the past and it also looks rather ugly. Anybody out there have one of these?