AJ's Opinion; what size SBM do I need

That's you, not me I don't give the 360 a second thought dinky bore and over stroked. imo
Unless you come up with a early 70s block, 72 and 73 then it's game on for 340 pistons.
I would not pass on the stroke either way, it's torque that moves the car and delivers gas mileage.
Come to think about it, if we built what we NEED it would be like Europe just little three and four cylinder box's not forty and fifty year old V8s.