I have to stop by work tomorrow, so I'll tell him the top recommendations. Thanks everyone for your suggestions.
Tell him to go .454 Casull or .480 Ruger in DA as you can go with heavier loads and thus less rounds for a kill. A while back young man killed a large grizzly with a S&W .44 Magnum Mountain Gun but it took five rounds. I have seen stories where others using these super magnums killing large grizzlies with one or two shots. The .454 Casull and .480 Ruger can handle bullets in the 360 to 425 grain range and have double the firepower of the .44 Magnum. The typical .480 Ruger commercial round is now loaded alot closer to its .475 Linebaugh parent and has devastating Taylor Knock Down values > 35 with 400 grain bullets. He can custom reload with these calibers and develop his ideal round. It would be best for him to test fire before making his purchase as the recoil and blast effects from these weapons is considerable.