Punch-Out has 110kg left to play with, I'd say use up as much of that as possible. Use the biggest, most powerful VDMA bursts, if you aren't already. Upgrade the front panel to steel, if it isn't already. Dunno whether it's worth upgrading the chassis armour or drive, but you might want to do that too, if you can.
Looks great though, I like the idea of using the chassis as the head rather than the base/torso.