Well, well, well......
Lets start out with Electabuzz. It has decent stats all around, with best special attack and speed. But defense is pretty bad, so an Evolite would help a little. But it would be even better evolved. So don't worry about putting an Evolite on an Electabuzz.
Dusclops would be indestructible with an Evolite. With AMAZING defensive stats you really don't have to worry about anything; you just can't deal a lot of damage. And, like trachy said, it is one if the best defensive walls in the game.
Hope this helps =)