If it helps, last summer Bontrager started selling the Inform Affinity, which is more t-shaped than the original Inform. In fact earlier today I put a 155mm Affinity on top of a SSM Aspide Glamour and found they are almost identical in size and shape.

The Affinity comes in different varieties regarding the amount of padding -- RXL, RL and R. And the 3 different widths.