from the side, the duc tail looks great. But not sure how it would look from the rear.
I feel like the evo tail would look great and give it the look that you want...and im assuming it would be tons cheaper than the duc tail/subframe.
the RR tails...just dont think they'd look right without the undertail exhaust.

 

That Evo tail looks nice.... bit of work but it'd be worth it. That red thing looks foolish. Itd would look like you got a carrot out ya bum while ridding down the road. Haha

 

You should see that bike in action. That thing is an absolute monster with it's rider at the controls.

(It's a MAD KUUSAA bike) They have some crazy youtube vids.