Yeah, I highly doubt anybody's ever made a serial Smart Media Card reader, if so, it would be horribly, horribly slow for transfering audio files. USB PCI card and a USB reader are the way to go, however, I'm assuming that if you don't have USB ports, then your computer is probably pretty old. If you're running windows 95, you're not going to get USB support (some rare later versions supported this, but nobody supports Win 95 anymore, so it probably wouldn't do you any good). Windows 98 kind of works with USB, though it's a bit sketchy, and if I remember correctly, USB 2.0 won't work with it. Bottom line is you might want to think about getting a newer computer or borrowing a friends for transfering the files.
The other problem, however, is that the storage on Smart Media is rather limited. Granted you could get 1 gb+ cards, but they're gonna cost you a good bit. I don't know exactly how much depth the files that your 4 tracks record have, but many times I find myself filling up half a gig or more on a single song with only 4 tracks; cards that hold this much will usually run you around 100 bucks or more, and you'll probably have to go and upload to your computer after every song (quite a pain if you want to go back and rerecord something later).
Point is, I'd suggest looking into a recorder with a built-in hard disk, preferably 10 gig or more. I have also heard of recorders with built-in CD burners, and if somebody else could give their opinions of those that'd be interesting, but I'd be a little warey of those due to the speed/space restraints of CD's.
