Just looking at the Crown Vick crossmember, I know it won't bolt up to the 54 Dodge frame.
I doubt there is anything that will bolt on to the 54 Dodge pickup frame without a lot of frame modification. Both frame rails on the 64 frame curve towards the center at the crossmember, and you will have to remove the crossmember. to bolt something up, you need straight rails. For the most part, that means you will probably be better off clipping the Dodge frame, and the Dakota will be the best match up, short of building a front frame yourself and bolting something to it.

I'm sorry if you are under the mistaken impression that modifying the entire front suspension is cheap or easy, and that something else fits it perfectly. Gene