I've got a set of new R2Cs. Take offs. $260 shipped.
You want a Quarq that uses a 24mm (standard) spindle (SRAM/Shimano/etc). Those mate with Trek's press-fit bearings in their system. I have some of those in stock too--used in SRAM S975 and Rotor 3D cranksets. What spider (compact or standard) and what length cranksets?
Brian Grasky
Grasky Endurance: World Championship Triathlon Coaching; Professional Training Camps RETUL fitter, Biomechanist, USAT Level 3 Coach, USAC Level 2 Coach