Assuming (!) you're staying with polo shirts, try the 5.11 Tactial Polo available from the usual variety of sources. Comfortable, long-lasting, a bunch of colors, and mine has a nifty pen holder in the sleeve. I think they're about 30 bucks.
I love the Blauer 8130 shortsleeve knit. They have epaulettes, two front pockets, and a badge tab. They're a hybrid between a class B and C. They tend to run a tad pricey, but they're super comfortable, keep you very cool, have the pockets/epaulettes, and look more professional than the standard polos.