you can buy whatever you want as long as it has the specs that they require.
the IBM is a bit dated and the DELLs are very good, based on what ive heard. I have an IBM R51.
The best part of getting it thru nyu id say is the 3 year warranty. But whatever, u can get that anywhere, and they lend out computers for u if urs goes down
Bottom Line: get the best bang for ur buck even if it means getting it elsewhere.