Texasfirearmfan,
Keep in mind also that Beretta has constantly product-improved the 92FS/M9 over the last 30 years as well, so that the new 92FS/M9 that one picks up in a gun store is going to be a little bit different than the 92F/M9 that your dad's "navy seal buddys" recollect.
That said, as tahuna001 mentioned, this whole discussion is moot because federal law prohibits both the sale of a handgun to anyone under the age of 21 and also makes it illegal for someone to purchase a handgun on behalf of a minor.
If I were you, I wouldn't even worry about it now - you've got a great 6 years coming up in your life anyway! It a good chance that that the Beretta will not be your first choice for a handgun in 6 years (as great a piece as it is, I wouldn't really consider it to be a great first, or even second, handgun).
And, if judging by all the great handgun options that have appeared in the last 6 years, there's no telling what we be offered over the next 6!