Which iPhone model # is the most globally compatible and still works on Verizon CDMA and AT&T GSM? And is the US Cellular model more globally compatible than the Verizon model? I'm trying to determine from this page http://www.apple.com/iphone/LTE/ Will Verizon provision a compatible phone even if I don't purchase it from them? And how can I buy this most globally compatible hardware? Must I wait til the Apple Store sells the iPhone 6 unlocked? I just purchased the iPhone 6 model # 1549 from Verizon but thinking of traveling south America, Europe, Australia, etc. Is there any one model that covers all networks?