I have a Large in the Dynasty girdle which, let's admit, is the same thing as the QRE pro girdle with modified back and kidney pads.
I combo that with a Small pro stock Warrior girdle shell, but it is the Reebok/CCM 9k version that just has Warrior branding.
The two are a great match. For added context on the Small shell size, it is made for Steve Bernier who is 6'3, 222 lbs. I am 6'1 187 lbs. I also read that the pro CCM 9k girdle shells do not vary drastically from one size to the next, but I have not had another size to compare.
Good Luck!