I can only think of one external sound card off the top of my head that, its a Hercules Game Theater XP. Instead of a front panel, it has a external break-out box that holds all the connections, except a Aux In jack on the actual card.
The box has in the front:
Headphone jack, mic jack, both with controls, Left and Right line inputs, 2 USB and a Gameport.
On the back is 2 speaker ports, both ports have RCA jacks and a center and a subwoofer port. Also there is 2 more USB ports, a Digital In/Out with both a Coax and Optical, and a In and Out Midi ports.
Price is kinda a killer, I got the retail version from Newegg for 142 shipped, as they were out of stock on the OEM. So it isn't very cheap, but so far I've been really impressed with the card. I haven't tried the Mic port yet, as I stepped on my head-set awhile back and haven't got around to fixing it yet.
Here is the offical link:
Hercules Game Theater XP
From what I've heard, there aren't any major Win2k issues, but you might want to check around on here first.