If you had access to these three vaccines, which one would you take: Sputnik V, Sinopharm, Sinovac

I would wait for a vaccine that passed muster in the EU and/or the USA. I don't trust either the Russian or the Chinese vaccines. I don't think they'd be harmful; I just don't think they will confer much protection. If you take any of them, you should still consider yourself unvaccinated against the dominant Delta variant.