My SO will be probably be finishing her program at the same time as me (3 more years), so realistically I won't know where I'm headed long-term in time for EIP consideration
i hate to be the bearer of bad news but this is rather problematic.
chances are, you will have to choose your destination city about 1.5 years from today (summer 2013). you will line up something through oci/eip which will lead to a summer internship, which will lead to an offer. you can do 3L OCI, but its rather sparse and there is no guarantee you can switch, so you will probably end up going to wherever you ended up for 2L OCI. and if you have the 2L offer, it is not worth forgoing for the hope of job searching after 3L graduation.
so either you will have to undertake a risky post 3L job search with little chance of biglaw, or your s/o will have to end up in your chosen city even if she can't find an academic job there. i would address this conflict before you decide on either school.
one possibility is a clerkship, which would have you doing your full time job search over 3 yrs from now (during the clerkship post-graduation). but that would require top grades and is by no means guaranteed at either school.