Well, might as well answer my own question, in case anyone cares about my opinion on this subject (I selected Arcazeus's, though, since it wouldn't be fair if I didn't.)
Bellossom can learn Acid, which deals damage to all adjacent foes and has 30 PP. Here's the set I have.
Item (if you want): Smoke Ball
EVs (if you want): 252 SAtk / 252 HP / 4 Atk
~ Dazzling Gleam
~ Petal Blizzard/Cut
~ Sweet Scent
Some good horde EV training locations