So after talking extensively with GT Haus I finally ordered the GT for the E90. Turns out that their newest version of the GT has the same exhaust across the board for a E90/92/93. They all use the same cannnister and are the same size as far as the body of the exhaust goes, the only difference is the tip length which is 3cm longer for the coupes and convertible. No more different canisters (barbell/indented, etc), they all have the same cannnister now.
Will post feedback on fitment once I get it.