Some people rely on VPN alone. I would not. Most bittorent clients imbed your real IP address into the actual data sent to the tracker. That mean that your connection may seem to be coming from the vpn's address, but still your real IP address is not unknown.

This is also true for those who foolishly download their torrents through TOR as well.

What you want is a seedbox. The seedbox you rent for a few bucks a month is what connects to the swarm, so your IP address will never be given out. You then download/upload directly(or if you wish - through a VPN) to the seedbox. An added bonus is that it will continue to seed for you without taking up your own bandwidth. Thus your sharing ratio goes way up and other users/private trackers will love you.

Although unlikely, the possibility exists that the seedbox company could give you up. This is also possible with VPN companies. A good seedbox company will not do this obviously - they tend to exist in jurisdictions that do not care about US copyright law. If you are really that worried about it, you could also just choose one that allows anonymous payment methods.