In which ivan variant I can beat the game without any "ultimate destruction" bugs? becouse I heard that in Ivanx (which I'm using) there is bug where you can't get through gc:8 or 7.
You can beat the game in any IVAN variant 
So long as you can get to Attnam you can always get one of the endings regardless of whether some levels in GC cause crashes.
That doesn't mean it'll be easy.
So long as you can get to Attnam you can always get one of the endings regardless of whether some levels in GC cause crashes.
That doesn't mean it'll be easy.