I think the real gotcha will be the DOS drivers.
The 802.11b DOS driver+hardware combo I know about is PCMCIA. ORiNOCO Gold is PCMCIA, has
MS-DOS drivers, has 128 bit WEP and was a highly respected card when it was new.
PCMCIA card to ISA slot ... I remember some bridges that have Windows 95 or Windows NT
drivers for the bridge itself. It's not pretty.
Tim.