Let me help you out. This is a good deal for someone wanting to try their hand at tuning. It is the same SCT Advantage III software the pro's use but you only have one key to unlock the 03/04 code. If you happen to have LaSota's training video with it, it would help.
Yes, The AMZ2 is just the latest code Ford used as a factory flash. This will work on any 03/04 Cobra. It will overwrite your YDH1 to a AMZ2.
It can do both, you need a handheld (Xcal) to tranfer tunes to. Or, you can burn to a chip but you have to buy the burner seperately (unless OP has it).
So... since it only comes with one unlock code, is the buyer going to have to purchase another ?
I've been through Don's training in person (granted it was about 6 years ago... and I haven't used any of that knowledge since then... my old '04 Mach1 was a guinea pig during the training of the guys at one of the the dyno shops up here. I got to sit in and learn it myself. Don was quite the guy.)
Rod