a 545FE from a 5.7 Hemi is about the only bolt in option you have without doing adapter plates. A 545RFE is a "5 speed" tranny, but not how you would think. It has 2 second gears, one for upshifting and another that is between 2nd and 3rds ratio for passing gear when it shifts down. You would also need a computer to run this trans and extensive floor modifications.
As for a regular 5 speed auto, I think you are SOL.
The gear vendors unit replaces the tail shaft and gives you more overdrive gears.