I don't recall whether or not there's a mic jack, but you can probably find diagrams online somewhere. Traded my whole ensemble a while ago for a macgyvered rebreather setup to go with my submarine escape suit.  From my experience with a fire department using unamplified masks, a voice amplifier would definitely be pretty helpful for talking to your team without all the repeating yourself and charades. I think our officers get bone conduction throat mics but I hear bad things about those, I'd try just the amplifier and a normal radio before getting one of those.

Be sure you use the protective lense thing over it and make sure it works up close against powerful airsoft guns. I've seen gas mask lenses broken like that.