In the OP he wrote he is using an AT&T sim card. Wouldn't that prevent him from being able to get the Verizon OTA? Like The Pagel wrote, using the ODIN file to get to 4.3 would probably be your best bet.
Shouldn't we treat this world like the garden of Eden and avoid the apple at all costs?
Sometimes you go to the circus.......sometimes the circus comes to you