Went down to the shop again today and found out more info.

The exhausts is 60.5mm OD, and the RM-01A is the best one out of the two, light weight and give more power gain.

They are doing an introductry sales on it right now. The RM-01A is around $1050cdn/$680usd. Still not cheap, but from the look of the quality, it should worth it.