If I were you I would get rid of the stock can for a Jardine and filter. Then remap your stock ECM with ECMspy or ECMdroid for free.
The magnaflow setup is $425 + shipping. Chin fairing brackets are extra.
Not a great vid but.....https://youtu.be/z_K4aNT1Cxk
Google it, bimmerfreak?I think it was has a nice ride by clip on you tube
They sound great very low and thumpy no tin sound. Not as loud as my d&d. I don't know the #'s but felt much stronger low and a bit better high than my d&d tuned bike. Which isn't a huge surprise if you do a bit of dyno test research, d&d isn't the greatest for power gain except in the middle,but I like em loud!