Here is a picture of the manual for a AC 2 way plow. It had both right and left hand plows so you could turn around at the end of the field, change plows and then plow the other way.
Not sure of all the options but all the "gear splitters" I have seen on the 8n's split before the PTO. Reduced wheel speed results in reduced PTO speed. I assume there is something out there to do what you want but at what cost? Depending on how much you are doing a plow and harrow might give you good results and its more fun!!!