IPhone and gophone? Will it work

I've been reading a lot of posts about at&t supporting iphone's us of prepaid plans and I just want to confirm what I've been reading.
If I buy an unlocked iphone 5, I can purchase a $65 plan and set up my data, text and voice without having to go to at&t to get my APN changed. Is this right?
The data plan in the $65 plan does work with iphone?

I would really appreciate your help! The posts have kind of been confusing

Data on the $65 plan will not work on smartphones.
you will get texts and calling.

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