Roserade: Roserade is a great Special Attacker, with a whopping 125. Its Special Defense is also great with an awesome 105. Its Speed is pretty decent, but if trained well, it can be pretty fast. The issue about Roserade is that its Defense is awful. If you get hit with a Physical Attack, that things done for, but still a pretty good Pokemon. It has a stat total of 515.
Octillery: Octillery is a great Special AND Physical Attacker. You don't have to teach just Physical or just Special Attacking moves because its Sp.Atk and Attack are equal. Its Defense is, OK, but not great. The bad thing about it is its Speed, it is very slow, which can give a disadvantage in battle. It has a stat total of 480.
Togetic: Togetic is decent. It is very slow but Special Attack and Defense are pretty decent. I would not say this is the best Pokemon to use because of its Speed. And even though its stats are pretty decent, there not the best. It has a stat total of 405
Sneasel: Sneasel is very fast and has a pretty good Attack stat. His Defense is not to good though because of its Ice typing, but Sneasel is a pretty good Pokemon. It has a stat total of 430.
So overall I would recommend you Roserade and Sneasel. Both are the fastest of the four you listed and both can be pretty good in battle if the right moves are taught to them, so teach Roserade more Special Attacking moves, and teach Sneasel more Physical Attacking moves. So, I would recommend Roserade and Sneasel to be on your team!