This is a nice symbolic idea for a gift, but don't be under the impression that it is something he will actually wear in theater.
What he wears in theater will depend on what type of aircraft he flies, and even what location he is deployed to.
Even then, type and style of holster will differ.
I've deployed several times flying both fighters and ISR aircraft, and the AF has so far purchased me three different style holsters for four different deployments...and those were just for administratively carrying the pistol when I was *not* flying.
Why?
Because each theater, and even each individual location, has different rules about what they want. For example, I deployed to Bagram AF in 2007, and I was issued a shoulder holster for the M9 that was a horizontal-carry style. Four years later, when I went back to Bagram in '11, the Army leadership at BAF had changed its mind and now all holsters had to carry the pistol muzzle-down, so I got issued a different holster. I'm deployed in theater now to a location that doesn't even arm up when not in the cockpit, so there's no holster issued at all.
As mentioned, that holster was for carrying the M9 on the ground only. In flight, I wore a survival vest that had an issued molle-attachment holster on it, as there's no room under the arms for a pistol in a ejection-seat airplane. In the ISR aircraft I flew, we were issued M4s that went into a rifle rack in the airplane.
Bottom line: He will be issued what he needs to match the specific local requirements where he goes and when he gets there.
