It really depends what you want to do with the system. The Sniper is a fully featured entry level system. It can do a ton of stuff but it is limited on extra channels. The Super Sniper has three channels of info and the Sniper XFlow is CNC machined with larger injectors for more power so those are two "in between" options. I wouldn't buy a Terminator unless you really need some of the features. Rich at FAST Man EFI is a board member and a Holley dealer. Call him and ask him which one he recommends. He'll provide you with some information and get you a decent price on the system that you pick. He can also provide you with an online EFI training class.