I think an underseat system similar to the r1's (can from each side angled in slightly so they meet at the tip of the bike. Prob not a hard mod to do converting high mounts to that with the right tools...

 

Not looking for something that goes under the tail. I really want to do something like the Buell but the buell muffler is to large. and would be to low on the bike if I mounted it under the engine.

 

My Two Brothers polished aluminum slip ons cannisters are 18" long. If you had a way to make a very straight cut you could drill out the rivets and take off the end cap, then shorten the cannister to 12" long to get the pit bull look, then reinstall the end cap which is what the guys on the ZRX forum were doing to their cans.

It looked pretty cool and at 12" long your end cap would end right about the back of the wheel. Since the cans are polished aluminum repolishing the end of the can should be doable to make it look like it came that way.

It would be louder though. To do the mod you are asking about would require considerable fabrication. Shortening the can would be a lot less work. Just a thought.

 

Here's what Suzuki did with the new GSXR 750 and 600. Not quite fully underneith like the Buell disign, but not quite the 'shorty' pipes.