What engine for my new Town Panel?

If you can do a 5.7, you can do a 12V. Just saying.
Having said that, the Cummins 6bt will put a fair amount of weight on the nose, but you will get better MPG.
I don't know about that. Mopar sells a kit with all the electronics needed for the 5.7 swap. I don't think motor mounts are going to be an issue. The 5.7 is supposed to bolt up to a SBM tranny with a flex plate I think. Only thing I am seeing to fab is exhaust?

I'm just not seeing any of this stuff available for a cummins swap. It would be cool though. I know there is one guy doing one in a similar truck, a 4bt I think.