This thread will give you the basics on what to look for when buying a used SCT.
What to look for when buying used SCT for 6.0
This next post is from SCT. The first post is what you want to read, pay attention to the last paragraph.
With that said, yes it's possible to use a different strategy. As for what strategies work per year truck, I don't know. What I do know is, strategy tunes written for the '03-'04 trucks will not work on the '05-'07 trucks, and vise versa. The two different group years don't have the same protocol programing.