I'm looking for some guidance and expertise here.....

Problem:
I'd like to run a 55/42 oval setup on my Trek Speed Concept with power.

I did some looking and feel switching to GXP with a Quarq DZero crank with Rotor rings is the route I'd like to go. However, I'm not sure whether I need the hidden bolt or non-hidden bolt option from Quarq to work with the Rotor rings.

Anyone have any experience with this setup or willing to share some other ideas?