First off, thanks for serving. Second, I think you make a good point with your story.
As far as a holster goes, I have a 5" Springfield Armory 1911 and I'm a fan of the Serpa holster I purchased for it. Its sturdy, doesn't scratch up the weapon and has a nice solid *click* when I holster it. I like it because your finger will naturally line up with the release button if you draw in a way to keep your finger out of the trigger well. If you are looking for something leather I would recommend a Milt Sparks holster.
If it were me, and I were attending school...I would conceal using one of the Maxpedition type packs. If you are a student and are "caught" OC'ing you'll be expelled from school and your transcript will probably indicate that you were expelled for "misconduct" or something equally tarnishing. You don't want something like that to turn up later in a background check, etc... Sometimes discretion is the better part of valor.
Hope this helps!