I like mallet heads for stamping. Never got used to a round maul. The weights I like are mostly an 4 oz one I made from UHMW and a 10 oz one I bought for larger stamps. For very large stamps like a maker's stamp, I use my drill press to make an impression or, on occasion, a 28 oz Barry King mallet. For BW, like you were asking, I use the 10 oz one.
In the photo: the 28 oz BK mallet, the 10 oz mallet and the 4 oz one.