Zipslack is not just a small slackware. It is a basic version of slackware compressed as zip to be installed on a FAT filesystem. You might as well install slackware and just be carefull with not selecting to much packages, same effect.
But to give linux a try zipslack is great because you don't need a free partition. It can be installed in a directory on a FAT partition. It is booted from pure DOS.
So for a carputer i sugest you use slackware.