If you're interested in a high-quality, free tracker, check out Jeskola Buzz. It's located at
www.buzzmachines.com.
Buzz has a pretty darned high learning curve. But once you get it, it's not really that hard. You should definitely check it out! For using samples, you're going to either use the Matilde Tracker or Unwieldy Tracker within Buzz.
Good luck!