I'm in the new market for a new phone and am currenting in favor of a new Motorola flagship device. I currently live in the USA and am planing on using Simple Mobile as my new carrier. Only problem I am coming across is knowing which devices will work on Simple Mobile. There are two phones I am looking at. The Razr Maxx HD and the Razr HD. I know that the Rodger's Razr HD I can get unlocked and its a GSM phone but I'm not too sure about getting 4G on it. I'm also wondering if I can get an unlocked Verizon Droid Razr Maxx HD (from Negri elctronics) will that work with Simple Mobile?

Where I'm getting my phones from:

If neither of these work, I'll probably just end up getting the Nexus 4. That will work with Simple Mobile right?