FYI every Russian submarine capable of launching ICBMs begin being tracked by the Orion aircraft as soon it enters international waters.
NATO attack subs are always there too listening very carefully.
Yankees are very thorough so the only place a Russian sub can safely launch missiles is the Arctic polar cap. That's why they're built to break the ice from beneath.
An Iranian sub won't have a chance of leaving the Persian gulf not to mention the Pacific ocean. Russia itself has only one Typhoon class submarine that is operational. Another two are held in reserve and yet another two are ready for scrapping.
Considering the sheer cost of such a sub I doubt any country would be able to buy it. And even if there is such a country I doubt Russia would be willing to sell it.