Don't pick your uni cos of your partner. A lot of relationships will not last throughout uni simply cos people grow and change. If you have picked your uni based on someone else then split up you will be bitter about it. Even if you don't split up, you may still resent them.
However if you have both chosen the same uni then that is different. I'd say its usually best not to live in the same halls & make your own friends. At the beginning you should resist the temptation to see each other too much or you won't make as many friends cos people will give up inviting you out. This might cause arguments but its probably best if you agree not to see each other too much initially, even if you are feeling lonely. After a few weeks when you have settled in, your relationship will be like those people that get together at uni. If anything does go wrong you have your own friends & your own space.
A girl I knew got together with a guy on the 1st night of uni. (She had known him before uni). He lived about 10mins away by bus, altho at a different uni, & spent all her time going to his. Because of that we never got to know her so well. I thought she missed out a bit by not making more effort at the beginning with people in her halls.