I think most clients will run on a macbook - Utorrent is a reliable one that many here use but there are others. You'll find that all torrents here will be virus/trojan free but remember that not all sites can say that so trojans can be found elsewhere so make sure you have something to block them on your machine.
If you are not familiar with torrents, make sure you ask us if you have any problems at all. We are happy to walk you through anything you are unsure of. We're nice like that
