Probably just Proton
Actually, the Zenit is not a Russian launch vehicle, it is Ukrainian. The geopolitical relationship between Ukraine and Russia is at the present time, a little tense. Hopefully, the Russians will be able to, over time, procure Zenits and their associated infrastructure, in a timely and business like fashion, without interruptions due to extemporaneous political friction. We’ll have to wait and see.
For the same reasons the Russians could not afford to fully fund Klipper, they may have similar problems with the development of Onega.
So I guess we’re left with Proton.