I have not seen one yet, but I think I would like a Detroit Diesel 12V53 with two or perhaps 4 turbos.
Then to make it even better it would be a silver model (bypas blower and crosshead pistons) and also DDEC (electronic controls / injectors)
They did actually make a few V12 series 53 Detroits, but less than 20 I believe.
More practicaly I would like a silver, electronic, 4-53TI
Grigg