Finding the cards is tricky, finding the drivers can be too...
What kind of laptop do you want the card for and what kind of games do you want to run?
If you intend to run DOS games on Windows 9x (on atleast a first gen Pentium I would guess), you might as well go for a card that offer SB DMA emulation like the ES1688 based cards or WSS-SB emulation like the Newmedia Wavjammer or WJ-SCSI combo card.
The parallel port Portable Sound Plus from DSP also has a decent SB emulation under DOS, if going parallel is an option, the device needs an external power supply or a good amount of AA batteries though.