They are all the best. It is hard to not find an excellent mounting system for the Mosin.
However, you may have parameters that you have not shared with us. For instance, do you want the rifle to remain in original condition? If so, that eliminates several options. Or, if you want an historical mount that was actually used in wartime, that limits your options too.
Google is your friend. Take a look at some of the images it returns and decide what you think will be best for you. Whatever you decide, I can pretty much guarantee will work. It is very hard to screw up anything on a Mosin.