Welcome to the Nation.
I don't think the mechanics of a swap will be that problematic. The issues, that will have you pulling your hair out, will be the electronics. The wire harnesses for all three of the engines mentioned, are different. When I say different, I mean that they each have different connectors for the PCM. If you chose the 2.9, you would have to try to use a 2008 PCM. Whether or not that would work in your 2007 is an open question. The PCM will need to be programmed. It's doubtful that the 2004 3.5/PCM would even work in your 2007. Before getting in too deep I would suggest that you find someone with automotive programming experience and get their opinion. You are going to need a programmer, anyway you go with a swap.
Just curious, what caused the 3.7 engine to be beyond repair?