I think the only issue you would find with duals would be how to route the pipe to the left side. There is not a lot of space behind the motor for an exhaust header to go through. In fact, it looks like you would have to gut the area under the seat. It would certainly be a grand project.
You can't shake the devil's hand and say you're only kidding.
2011 900 Custom SE
Cobra Swept Exhaust - Black
Cobra PowrFlo Air Kit - Black
Cobra Freeway Bar - Black (painted)
Kuryakyn ISO Grips - Black
Kuryakyn Contour Throttle Boss - Black