Depends..
How broken is the mangekyu techs compared to the Rinnegan?
I'd say that there are some Mangekyu that are more broken than that Rinnegan. For example: Kamui.
If Obito had access to one or both of his Kamui abilities then he is untouchable (he needs to be simultaneously attacked in both dimension).
So 1 Rinnegan overlayed over one of his Mangekyu is more OP than having 2 Rinnegan (I actually don't remember his Rinnegan tech or if it ever was shown. I'm only going off on Limbo and Ameno, which are unique abilities to Madara and Sasuke respectively).
Based on the featured feats, I would go for 1 Rinnegan, 1 Mangekyu. You have access to Susanoo, and your 2 other Mangekyu abilities (still wondering how Obito's didn't work but Sasuke's did).
Resizing (Isshiki) and Reflection (Momoshiki) are great as well but IDK... Against a working double Kamui + unique Rinnegan ability. I doubt that.