there is no industry standard club length. club manufactures increase their length and advertise more distance and all the manufactures make the head at the same weight give or take a gram.
if the club you are playing now feel heavier to you than a set you picked up in a store its because the shafts are lighter than what your play now, not the head. different manufactures make heads in different weights in hybrids and woods but most iron heads are the same, ex. most lob wedges and sand wedge heads weigh 300 grams and they get 7 grams lighter as you go up the set.
i would like to ask cause i didnt see it on earlier posts what are you playing now?