Is stockfish or komodo better?

Stockfish is better. Here a currently running test match between the latest Komodo 11.01 against a Stockfish version from early June (time control is 60m+15s): http://www.fastgm.de/pgn4web/live1.html
Not really, Stockfish took over as the strongest engine at some point in the last year. Since then a few new Komodo versions were released, but neither of these were stronger than the Stockfish counterpart. The latest version is somewhere on par with Stockfish 8 aka the version from November last year. Figure that the latest Stockfish versions are already about 20 elo stronger than that.
And neither of them has ratings in the 3400, you can´t compare that to human ratings. It depends on hardware you use, search depth etc.. but yeah Marco is right. I think the more interesting factor is the price, well Stockfish is free and that automatically wins.