This is a loaded question I am afraid.
Before you can sensibly specify a network machine, you need to know what the machine will be used for.
For example, a network machine being primarily used for office duties, word processing and the occasional spreadsheet or data base, can clearly be a lower specification, than one used on a network for CAD/CAM!
However, you have been told that it is for a college, so would it be fair to assume, some graphics, a fair amount of internet research(?), normal word processing and general office duties perhaps? Maybe you are in a better position to know the use than me, if your assignment is college based!
You also have to keep in mind, the budget that a college may be able to afford, and therefore, inevitably, there will be a compromise, between what may be ideal, and what is an affordable option.
Personally, I think you would be looking at a mid priced machine, with a good performance level, but not at the power user end of the spectrum.
The upgrade path (in my view), is a red herring. Computer's specifications change so fast now, that upgrades will not be an issue. Most organizations that need to upgrade, will plan about a three year cycle.
It will be interesting to see, what others feel on the subject.