I would personally shy away from the SMC Wireless offering. My two 7004ABWR needs constant rebooting (buggy firmware?). I hear this from many SMC 7004ABWR and 7004VBWR owners. Further, from the amount of returns I saw at Micro-center (at least 1 dozen at any one time) many others are having a tough time with the SMC wireless routers too.
Interestingly enough, I replace the wireless version with a SMC wired version (7004ABR) and it has been rock solid!
On the PC-CARD side, I believe they use the cheaper Prism II chipset which has a low transmit and receive sensitivity. However, they are cheap. I would spend an extra $20 and pick up an Orinocco Silver for about $40 which has a very good transmit receive capability, not to mention you can add an ext. antenna.
Doug