Okay, I really need your help????

I would like to know the advantages and disadvantages of these turbos.
REV-HARD
F-MAX
DRAG 3
And GREDDY

On all of these systems, if they dont come with a intercooler, i would buy the intercooler, so i would probably get the RH step 2 turbo, and with the Greddy i would have to buy the intercooler, and i think DRAG and FMAX come with them.

I was reading other posts and i saw that sombody said the REV-HARD kit is best for my car (B18B). But why??? If the RH, FMax, and DRAG all use the same turbo, why is the RH better for the B18B????
I am a little turned off from DRAG cuz i heard that it takes a lot of maintanance to have these be safe for my car.
And im turned off from Greddy cuz there kit is already pretty pricy, and then to buy and intercooler on top of that...

So basically im looking at the REV-HARD and F-MAX, and maybe the DRAG 3 if sombody can tell me something good about them??? Thank you.

Sorry for the long post.