I know a little about operas, but now tht much. Also, I am know a little about Prokofiev so I say go with him. :P I do not recall Shostkovich..I believe..meh. >.< Sorry I could not be of further help.
Help please for my music project!

I know the composers but not their operas. Probably the main thing you will want to talk about is how they had to exist under the Soviet system. The "Modernist" style that was current in western Europe, particularly the 12-tone music of Schoenberg and his followers was strictly forbidden. They were required to write on themes of "Socialist Realism". This not only limited the subject matter or story of the opera but its musical style as well. But they probably managed to work some very subtle criticism of the state past the censors. I know that Shostakovich called his 4th Symphony "A Soviet composer's reply to just critisim" but many have interpreted the work differently. Hope that gets you started.
Hi everyone, its good to know there's a classical music group on chess.com, which is really cool!
I have to do a music project on 20th century Russian Opera on the composers Prokofiev and Shostakovich, which operas are best to write about that represent their style and compositional characteristics? Thanks