your tuition is only $200?
Get the 680 for sure. It has 1500 cuda cores, which is key for any pro application that uses it (resolve, after effects, etc.)
Save up some extra money and upgrade to the 680 and upgrade the processor. you can always add ram and hard drives later.
OK, thanks everyone for all the input.
Looks like the 680 it is.
The main thing I'm concerned about is how much more heat and energy consumption will be created with the heavy duty gpu (especially as the new iMac is much smaller in the back).