G
If you flip the cylinders you are back where you started. Exhaust pointing forward and intake to the back. Only now you have waterpump and oilpump turning the wrong way and clutch at your right.
If I would use some snowmobile engine I would take the clutch out and put chain or beltdrive between the motor and the clutch. Clutch would be better located at the same side of the belt as the motor. That way it would be some 200mm/8" less width and more cenralized mass.
I had thought about that as well but then I realized the clutch doesn't stick out any farther than your leg anyway and it just adds a bunch of complexity and failure points.