Well its obvious that he has good taste. How else could he pick someone like you to buy him guns.
That being said, If an inline muzzleloader is what you want to get him, then you would be hard pressed to find one better than the Thompson Center Omega or Triumph. If you are leaning toward the traditional style muzzy, then either the T/C Hawken or Lyman Great Plains Hunter are the way to go. Good luck. And if things don't work out for you and him, you can always buy me guns.....