My biggest concerns are the fact that he is a low speed guy with a high track. Unless you put weaker drillings, those ball with stronger cores will more than likely die before it gets to the pins. A high track typically will make a ball want to rev up faster and the fact that he has a slower ball speed, a stronger ball may not be the best matchup. My first thought, is to take something like a Freeze Solid or Freeze Hybrid and put a medium strength layout in it; not weak, but not strong either. A low ball speed player wont want something strong unless he is bowling on 42+ feet of oil. If his rev rate is fairly low, even a skid snap ball wont be a true skid snap because of the lower rev rate.
I am in agreeing with Charlest here. With his profile, a stronger ball wont always equate to a stronger hook because he risks the ball dying by the time it gets to the pins. In his case, a weaker ball will actually appear stronger because it is able to conserve more energy going down the lane and give him extra help on the backend of the lane. The Freezes have a strong enough cover for most conditions he will see but a simple enough core that it wont want to roll too soon and quit.
Also......if he really wants Hammer, look into the Vibes. The new Cobalt could be an excellent choice.