Livernoise, you have to pay to unlock the tuner, and that includes your tunes as well I believe. Something like $400 or so for that.
SCT tuner (will have to use Unleased or AJPTurbo, a Member on this forum, as livernoise does not support it) - Unless it has been locked (married to 5 different ECMs) once the previous owner unmarries and returns his/her car to stock, you will just need the tune files
AJPTurbo charges $150 for the tunes, and IMO is the best option. I believe the unleashed price is similar, but with less tunes.
Hope this helps.