The Rotor crankset will not work with BBright. You will need a 3D+ crankset, whereas the crank offered by quarq is the 3D version (not BB30).
The S975 GXP "technically" does not fit as of yet (as the adapter for the GXP is currently in transit), but several mechanics have made adapters that work with the frame. The S975 with BB30 will work with BBright.
I just went through this drill and ended up going with an SRM (I preferred Quarq for cost, and to a tiny extent, looks, but I needed to go with SRM due to my specific needs). I talked with Quarq and the 3D (not 3D+) crank WILL work with BBright, BUT you have to use an adaptor that allows the use of the 3D and its 24mm axle rather than the 30mm axle that you should be enjoying with BBright. So you're losing the structural advantage of BBright over BB30.
The only "true" Bbright Quarq crank right now is the S975. Which is a great choice for BBright if you're happy with the rings that come with it. But IF you want to run Q-Rings on your crank (which I do), then Quarq told me you will not get accurate readings with the S975. You CAN run Q-Rings with the 3D Quarq crank, but again, you're using an adaptor and a 24mm axle.
I asked about a 3D+ version of the Quarq and was told they were just discussing that during a morning meeting today and there are NO PLANS to come out with that crank - I'm not saying they will not at some point, and I don't know their product development cycle, but I was told there is literally no timetable whatsoever for a Quarq version of this crank.
So to summarize: the only "true" BBright Quarkq crank is the S975, and you need to stick with the SRAM rings that come with it. If you want a "true" Bbright powermeter crank and also want the option to use Q-Rings, SRM is your only choice (I spoke with them this morning, confirmed that Q-Rings do not affect the power reading and was told that if I wanted my SRM crank calibrated at the factory with Q-Rings, I should call Rotor to buy the rings, and have Rotor ship them directly to SRM - both companies happen to be in Colorado Springs so apparently this is quite common).
Good luck to you.
S5 VWD | 9070 di2 | Rotor 3D+ SRM | Enve 6.7s
SuperX Hi-Mod Disc | SRAM Red | Rotor 3D+ SRM | Zipp FC 303s
P5 | 9070 di2 | Quarq Elsa | Zipp 808 FC CC/Super 9 Disc CC
T1 | Scatto | Rolf Prima FX58 / Zipp Super 9