[Carrier] GoPhone Prepaid Brand to Gain iPhone

Guys!I am coming to US for short visit with my european iphone 5 and 4.
I need a working 3G(i understand 4G will not work with my A1429).
The article from MacRumors says AT&T have updated PrePaid plans and now they support iPhone Data Acess.But AT&T support says they do not support Data even on 60 $ prepaid plan.What is the true?
which carrier/plan do i need to use my iPhone 5(A1429) from Europe and iPhone 4 with 3G in US?

Thanks