You could easily switch the entire fuel pump assy between the two and move the pump from the PTO to MAG carb. The main portion of the carb is the same, it's just the pump components contained in that stack of parts on the pump side.
I don't have it in front of me to look at but I'm not sure if you can rotate the cover to get the inlet facing the tank instead.
I think you are still going to have the same amount of hose length because you need an IN and RETURN line, no matter which carb has which function.
And to mikidymacs point, there is more than enough fuel with one pump. Maybe you would be more interested in running a dedicated standalone Mikuni pump?
What's your end goal?