I use bittorrent with a G card, but its a cardbus card and I think you're aiming for Pci correct?
http://www.linux-wlan.org/docs/wlan_adapters.html.gz
Any of the PCI cards that are PrismGT or atheros should do fine, I'm using a PrismGT card, which is actually natively supported in the kernel, but takes a firmware load you can snag off of
www.prism54.org
I would recommend a Netgear or SMC for nothing more than they tend not to change the chipset without also changing the model name, so you are almost certain to get the chipset you think are buying. D-link and Linksys have often swapped chipsets and kept the same model number, and it can be hastle prone.
Cheers,
Finegan