Hey neofree.
I don't know anything about physically getting the PCMCIA card into the case, but I did get my card running on my unexpanded 1200. You're looking for a Prism 2 or Prism 2.5 card as far as I know. It will have to be 16 bit and 5v. I used a Netgear MA401 (or something similar to that model, can't remember the exact model number) and it worked fine with a 3rd Party Driver. Check out
this page. I downloaded the driver from that page and it worked great.
