I'm driving the prop from the PTO end.
Is there a significant reason why most engines put the PSRU on the rear/transmission end? The only thing that I can think of is maybe crank thrust bearings and the harmonic balancer.
The front of V engines seems to be more easily adapted to a PSRU, once you remove the accessory belts and switch to an electric water pump. Rigging up a pulley for the alternator off the rear of the crank is dead simple.