nath180,
I was going to modify a takeoff '13 muffler and use that but now having tried a quality aftermarket muffler I would never go back to overly heavy and restrictive stock unit design.
If you like the '13 stock muffler general style and look but want to try aftermaket, you might want to check out the Graves slip-on muffler. If I had not bought the Vance and Hines, the Graves is a very nice standard length slip-on I was considering. Has a cool deep sound to it too. Might even be a little deeper sounding that the V&H CS One.