I have 6 Amfleet cars which run as a unit. I put a MT 1015 body mount on each end of the set to couple to my Life Like F40PH. This requires a bit of surgery to remove the mount for the Rapido.
I kept the Rapidos within the set, but replaced the long shank couplers with short shank ones off some Bachmann freight car trucks. Not very close coupled but closer than they were.
I did think of putting MT Commonwealth passenger trucks on the cars but the distinctive Budd inside frame trucks are part of the appeal of the prototype.
On the down side, the Bachmann trucks are pretty bad even for Bachmann. I only just tolerate them and they frequently derail. There is a challenge for MTL or any other innovative manufacturer to make a decent, free running replacement that still looks like the prototype.
Longer term I plan to try kitbashing some Amfleet cars into SPV2000s, but that's another story!
Cheers
David