I have two IBM A31p laptops which do not currently support my Linksys
WRT54G router's WPA2-PSK encryption on WinXP SP3.

What is the recommended wireless networking card nowadays?

It would be nice to be inexpensive but also allow an external antenna in
case I needed extra range (I sometimes try to go wireless in the back
yard).

Since the old IBM A31p laptop has only 1 USB port, it would be best to be
PCMCIA for the wireless networking card.

Any suggestions for a good cheap wireless network card (that allows an
external antenna)?