I was thinking of getting this for playing bass on but would that be good or overkill? I am a big metal player and I want something that will make my sound stick out.

I was also thinking about getting the Ibanzez PD7 since its half the price and looks to be almost as good and its made for bass.
I dont see why not getting the Metal Muff. I let the bassist in one of my old bands use my Digitech Death Metal Distortion Pedal and it didnt ruin it so it should be fine with the metal muff.