my buddy has them on his 2014 SGS and they look and sound fantastic

 

D&D Exhaust down in Ft. Worth will have a Fatcat 2 into 1 system for your bike that will give you exactly what you're asking for. Best system out there, bar none.

 

This was on a 103 mind you but when I installed CFRs it took away from the bottom end quite noticeably. Don't know how they would react to an install on a M8. They do have a great sound but definitely not my #1 choice.

 

Ok, so I just removed my factory baffles from my CVO Street Glide and installed my Fullsac CVO power cores, techmat blankets and perforated sleeves and I have to say that I absolutely love the deep throaty sound of them now. I'll upload a video tomorrow but man, what a difference and for a fraction of the cost. Hats off to Steve and his crew at Fullsac, I'm a true believer in their products.

 

Here is the video of my 2017 CVO Street Glide after I installed my Fullsac CVO power cores. The video was recorded with a GoPro and the sound is great but really doesn't do it justice compared to listening to it live. All I have to say is thanks to YB and Dave for their advice in going down this route and to Steve and his team at Fullsac for their outstanding product.