I think that if you really want a monster set I'd go Engine Guardian; however, imo a sorc will get more benefit out of using 2 5-piece sets and domihaus as icy-waffles said.
I always had the most success with infernal guardian. It procs frequently and reliably and adds fair burst damage. Also aoe.
Maw of the infernal can be fun too for pet builds. It at least interferes with a players ability to attack or react to your attacks when a huge daedroth is in their face.