[Maya] Rigging Recommendation Setup using Joints & Blend Shapes (Morph Targets) for a Chainsaw?

I have a low-poly game model of a chainsaw (1500 tri-poly total) to be used in my game. I need help recommendation on what would be a good rig setup for this weapon. My game is a first-person shooter with human characters as the player and enemies. So there will be first person animations and 3rd person animation required. It has been a long time since I have rigged and animated a weapon for a game engine. My chainsaw model also has individual chain blades circling around the chainsaw blade. I want the chains to go around the chainsaw blade using blend shapes from 0% to 100% and loopable inside of UE4 with adjustable speed. There also needs to be a parent joint at the handle, I think? for holding the chainsaw with two hands? I will greatly appreciate any help. I have share some screenshots of my model to help you visualize a starting point. I have no clue where to start.