What are the most likely Donor vehicles for the A 500 4 speed automatic?

O/T but..........I wish I was younger, smarter, and had more money. I'd LOVE to find a great solution

For awhile, I thought the answer "might" lie with something like a 45/ 545RFE, but John Cope does not seem to think much of them, and IN fact has a video about putting a 46/7/8RX backwards swapping where an RFE came out. Manual VB I think. Evidently the RFE is weaker in at least one gear than I was aware of.