Will this AT&T GoPhone and iPhone 5 activation plan work?

-Currently have Verizon account with 3 lines ([Daughter, son, wife] wife not in any contract) My kids contracts expire in October.
-Plan on switching to ATT.
-I want to open a family account with my own new line, and port my wife's phone number to another line. (and then add my children when their contracts expire)
-I preordered two iPhones to save for my children. My wife and I want to use AT&T Z331 GoPhone Prepaid phones.

-So I plan on purchasing the two AT&T Z331 GoPhone Prepaid from ATTs website with the pay per use plan. (don't use them till later.)
-Open the iPhone lines under my wife and I's lines. (get the required data plan, Nation 550 Family Talk plan)
-Put the iPhone SIM cards into the GoPhones (I bought some nanosim adapters)
-Cancel data plans

Essentially now having the GoPhones on our lines, in the family account, and having the new iPhones ready for my children when I add their lines. (update our plan because Nation 550 Family Talk has 3 max lines)

Will this work? Do I have to worry about the plan I got from purchasing the GoPhones, anymore?
Please let me know if I'm missing any detail

Are you trying to do this to avoid paying for data plans for the iphones cause as soon as you put those sim cards into the Iphones, they are going to start pulling data and AT&T will catch on and you will get a bill like no other. No matter which way you look at it, by the end of Oct, you will have 4 phones and all will be on contract if I'm reading this right and 2 of them will definitely need data plans cause like I said before, you need data plans for those Iphones.
Also, when you buy Gophones online, they make you buy a package of some sort, like you'll need air time cards for each phone in order to activate them.So, if you don't activate them until you go on contract, you'll be wasting 2 $25 air time cards.
Any way you look at it, AT&T is going to charge you for the data once all phones are activated and those Iphones will use up data and you will pay big time.