Whats the difference in e-fans?

[Goldcuffs]

I've been reading and searching about the e-fan swap and I have everything figured out except the difference in the fans between the years. It seems the 07 and newer fan is different and substantially cheaper(in the aftermarket anyway). Can anyone tell me the difference? If I'm going to spend the money I'd like to get the better set. And yes, I am going to use factory.