Upgrade my Mac Mini

I have one early Mac Mini Intal Due, serve as my iTunes and email computer. I have upgrade to Snow OS, I know that can not upgrade to the new OS. Now I decided to upgrade to the new I5 Mac mini. What best option to move everything from one to other, I have a 1 TB FireWire as time machine right now use that as option 1 or wipe that FireWire drive just copy everything over, new Mac mini what point tell go get files, setting & Apps.