I noticed almost all legendary monsters are on sale ins shop for either 230 or 276 gems.
Would any of you recommend me some good attacker?

I'm mostly interested in some monster that have more AoE attacks.

Right now my main attacker is Pinky Flash, but only good AoE is "Jumping Hams". Is there any monster out there that might have 2 skills like that?

No monster has 2 50 Base Power AOEs. But there is monsters with 2 45 Base Power AOEs, like Kiridar and Granuy.