Ringo,

Here is a link to a great article written by our own Todd Wilkinson:
http://www.scottishtartans.org/USAF.htm

Here is a link to the USAFR pipe band, showing the USAFR tartan. if your father wants to purchase a kilt that is connected in some manner to his military service, that's what I'd suggest.
http://www.usafreserveband.af.mil/ph...galleryID=1274

That being said, I'm not sure that the USAF uniform regs allow for the kilt to be worn with mess dress. As a retired member of the USAFR, I suspect that he is still subject to those orders. I'd encourage him to wear regular civilian Highland clothing appropriate for the occasion. He shouldn't be as worried about showing you up as taking away attention from the bride...

I'm sure, however, you'll get plenty of feedback here to encourage your father to "just do whatever he wants."

Best of luck.