I have years of experience in repairing/ programming iphones, so I hope I can help some people. I also own an unlocking server and specialise in iphones so can also offer Factory Unlocks if its any help.
I have been selling Iphone Factory Unlocks for around 6 months and have done around 300, not all networks are supported but i am adding all the time. Foxconn are the manufacturer not the software writers etc.
The factory unlock is done via Apple/ Itunes and is logged with Apple so the phone will remain unlocked even if you restore/ update