Help with best iMac for $2000.00

Well I'm guessing you're eligible for education discount which is pretty significant. For $2000 (and discount) you can definitely afford the 27" and it sounds like you would get good use out of the larger screen if you're watching movies and stuff. In terms of memory/storage/processor upgrades I guess it kind of depends on what subject you do... a doctorate in video editing or something would have pretty different needs to a doctorate in languages for example. If I were you I would upgrade the RAM to at least 8GB (either through apple or if you're comfortable with installing it yourself then it's cheaper elsewhere).

 

First wait with the purchase seeing you only need it starting in the summer. Hopfully by that time a new version of the iMac has been released.

Definitely look at the 27" model. Don't get ram through Apple but buy 3rd party ones (Corsair, Crucial). Will safe you a bundle of money which you can use to purchase more software/accessories.

When ordering the Mac, look at upgrading the graphics card. HDD is possible but not necessary.