sneaky_charm,
That's unfortunate that you're required to wear a uniform - I love being able to have access to different outfits, especially after taking in information from GC and other places. My go to is Guess, and I was pleased to see that Chase recommended it after the fact I'd already been buying from them.
Good suggestions by Regal. I think Darius is a great source and an expert in sexy men's fashion. If his detailed readable content make your headspin, perhaps you'd have an easier time listening to his podcast with GC,
found here.
The only thing I would throw in that I didn't notice from quickly looking over this was adding a subtle touch to your uniform. Because you're wearing a "cookie cutter" outfit for your school, you blend in very easily. Normally, I would wear a subtle addition to my outfit in order to make it pop enough for girls to notice, but not enough to be peacocking, such as a watch, necklace, or great color coordination. Personally I love my wardrobe and enjoy leaving my house the way I'm dressed, and normally that is received well whether it be unconscious/implicit/whatever.
I would recommend you wear a watch / belt / shoes of the same (or complimentary) color, but to make it a color that POPS from the rest of the outfit, like red, blue, or if you think you can get away with it, purple (those are my personal favorites with black/white, more pronounced or darker shades). Color coordination of your accessories will create that effect much more than the color consistency of the entire outfit, in my opinion.
The point here is that you do what you can to stand out in a situation you're more or less limited to doing so, in a way that isn't peacocking. I would probably even try to get away with unbuttoning a thing or two and bending the rules to whatever way you can that's sexy (if you guys have to wear ties I would undo the tie and buttons a bit and show off some chest hair, for example). I dislike forced uniformity in most occasions.
But hey, at least you'll be looking dapper more often than not (;
Hope this helps.
Hue