If the game have russian speeches, does the english version keeps it?

Because if it doesn't, I'll look for the original version.

English version = English voices and text.

The english version does have english voices and text, yes, but as I understand it, Ice Pick Lodge wrote a whole new script for the international version. So it is not as though the voices for the English version was poorly dubbed from Russian by an uninspired third party.

I also understand that people were much less pleased with the original script than they were with the English version, so you may wish to take that into account when deciding what you want to buy.