Dhoni is nowhere near as good as Boucher. Boucher wins that hands down. Boucher is one of the best keepers ever.
And Dhoni? Dhoni is a superb gloveman and his ability with the bat is well documented, especially since taking over as captain. However, I must note that this analysis is subjective rubbish, Harris Vs Harbhajan and Ntini Vs Zaheer are far closer than you made out and it need not be said that Test cricket is played by teams, not groups of eleven individuals. Heck, you have plain ignored Kallis' bowling, the effect of two 145kph quicks for South Africa and the fact that a player is not totally useless if he is worse than his Indian counterpart - this is why player-to-player analysis is fundamentally flawed.