whoa!
I'm not a big brand-follower but of that list i know Cooler Master and Antec definately have good reputations. Dont omit Cheiftec/Chenming either. Much as i have little to zero knowledge about CompUSA, i'm not exactly surprised a CompUSA guy told you the best case they had was a CompUSA one
Some people like airvents at he side of the case, others dont as dust gets in that way. Generally preferences seem to be for an intake area at the lower-front of the case (with some ability for using dust filters), and area for exhausting the hot air to the upper-rear of the case. I'd look for having two 80mm fan vents at the front and two more at the back, or better yet one 120mm fan at each.
The "best" case for you depends on a lot of things: price you want to pay, noise tolerance, number of drive bays needed, how often you'll be fiddling about inside it, and so on. If you really want airflow you could get a ThermalTake Xasier III and crank all the fans up to max, uber airflow - shame it sounds like a busy airport. You could also get a Coolermaster ATC-210 and have 4 screaming Delta fans in it, again loads of airflow at loads of noise, but alternatively two medium-speed Panaflo fans in the same case would be really quiet and is likely to be ample airflow unless youre overclocking like a madman. Most
decent cases will have decent enough airflow to make the main difference in cooling be the fans used - and you can swap these in all cases.
Cooling is not the main factor in case quality though, there's build materials - aluminium is weaker than steel but looks better and is a lot lighter, well engineered aluminium case will be plenty strong enough; its more expensive though so for some steel is a better choice. Then there's deisgn - Coolermaster ATC-210 is nice, but the price a bit hefty. Noise - Antec Sonata has 120mm fans and deisgned to minimise noise, some dont like the looks though. Portability - Antec LANBoy nice and light, designed with people who transport the case regularily; not the greatest cooling though perhaps, but fine for most people...
If you need a PSU, i'd say the all round best case is Antec 1080AMG. Unless you go to LANs that is...