The Chalnoth of Chalna would be a good choice, except they are anarchists and probably wouldn't be able to hand the relatively lax rules on an Orion ship let alone a Klingon one!

The Axanar could be a possibility, perhaps even the Suliban, though it would be more likely if they continued to exist into the 24th Century that they would be part of the Federation.

There just aren't that many documented aggressive species in the Beta Quadrant to chose from.