Newest version of Pfsense (1.2.3) and the card was one that was recommend on another post (Linksys WMP54G Wireless PCI Adapter 54MBPS 802.11G).
I suspect you might not have searched sufficiently extensively. For example, did you notice http://forum.pfsense.org/index.php/topic,21286.0.html
I've had a couple of Wireless USB NICs with ralink chipsets work fine, but the negative reports on the ralink PCI devices would keep me away from them, unless I was prepared to debug the driver. Atheros based PCI cards have had good reports but some contributors to the forums have had trouble with them on pfSense 1.2.3 RELEASE. (1.2.3 RELEASE seems to work fine with my Atheros based card.)
All this makes it difficult to make a recommendation other than to lodge a problem report with FreeBSD or try one of the 2.0 snapshot builds and see if you better results with your card.