The -7 and the -5 are a designation of the different size of the turbos. Please dont ask which one will suit my need, as I know of at least 5 threads that cover this in detail.
Supporting mods would be
Bigger injectors
fuel pump
free flowing exhaust
Cat is a few bolts and time to get a hernia when cracking the old bolts. Brand? Doesnt matter, get a 3-4" body cat with matching inlets to your exhaust. 100 cell.
Pods.... You know you need two right? and you need adapters, and you know they are defectable... and that people have run 400kw on the stock air box...
ummmm.... you forgot the best ecu, link (haha, haters gonna hate) WHY?! Because I said so, jk, it allows you to run map, and eflex. It will open your world for less than the haltech and for more than the powerfc.
I went from a powerfc to link. Link doesnt give me that annoying miss on cruise.