If you insist on buying a prebuilt PC, get that and buy a second graphics card (HD4850 is a good choice) from MSY Technology Pty. Ltd.-The Name you can trust-more than 10 years in computer industry and replace it yourself.
The margin the Union makes on those things is usually extremely narrow so offering an ACCESS discount on them would probably equate to making a loss, so no. Also there will be a cafe in the new law school, and the Fisher Coffee Cart is on its way back as well.
Go the dual. Games don't take advantage of the quad yet.
EDIT: Also they're 99% of the time going to be GPU bottlenecked anyway so the processor won't matter. Go with the 3.0GHz dual core unless the difference between that and the other one is <$20.
I'm talking about isolating (in-ear) ones which basically form a seal over your ear so minimal outside noise gets in. I had a pair of Super fi 4s and they worked amazing apart from the fact that if I wanted to take a call I had to pull one out to hear my own voice.