I like the MPPSK exhaust because of the two valves that make it a straight pipe when I want (in Sport or Sport+) - love the control I get with respect to noise levels.
If you want to purchase the exhaust separately, I think you'll need everything listed in the following link except for 03 & 04 which are stickers/decals (note these are CAD pricing):
https://shop.bmw.ca/a/BMW__/73227449...t/03_0220.html
To be honest, I'm surprised myself that these have individual pricing as I've always read it has to bought as a kit. Question is if you can find a Dealer who would order these parts individually if you don't already have the MPPSK installed.
If you only care about sound - go with another exhaust as it'll be less costly.