I have killed a moose and big bull elk with 160 grain accubonds. Bullets recovered were perfect mushrooms against the hide on the far side with 85%+ weight retention. Neither animal went far and they are wicked accurate out of my Savage 7mm. Cant ask for more than that.
Check out Research Mannikins online catalog. They have the largest selection of lifesized Mountain Goat forms that I know of. Do you know the measurements of the hide? That will narrow the selection some if you dont want to involve a lot of alterations. You should be able to find something on...