The Raven type would be a good start. Perhaps as a heavy engineering craft. It would be equipped with shield extends and hazard emitters, and be armed with some kind of point defense phaser and micro-torpedoes.
I've never heard someone suggest an engineering style pet but I can't help but admit it sounds like the Feds. A pet with EPTS, Engineering team and Extend shields 1 could be pretty decent. I don't know what kind of offesive powers would make sense besides beam overload or AP:Beta.