Add STR req to metal gloves, they weigh more than a power fist.
Decrease the 140% mechanical resistance and threshold penalty to 120% specifically for metal gloves.
Heavy Punch - Added bonus damage equal to twice the percent of the weight of the combat glove.
Guard - Have Guard give a bonus to the amount blocked by guard equal to the AP cost of a fist weapon.
Heavy Metal - Heavy Metal should also apply to metal combat gloves.