I would rather go through a server that I have already worked with like Sprint or something that way I won't have to make a huge deposit. Does it have to be AT&T?
umm you can just buy the iphone and then unlock it.
then use it at another network.
but you might wanna chek on the networks, make sure they use a sim card.
Right now AT&T is the only server that complies with the iPhone. There are iPhones in Europe, however, that work with what ever card you put in, maybe you want to look into that if you really want to hold on to your old server.