BU is probably the most prestigious of that group, but I wouldn't pay that much more to go to school there unless you were pretty committed to practicing in the east, specifically Boston or New York. In addition, it seems like there's a lot tying you to the midwest (family, significant other, etc) so that's a serious consideration too.
My brother is currently a 3L at Wisconsin - if you haven't visited, Madison is beautiful (although cold in the winter) and it has a great college town feel. Even among grad students there's a noticeable sense of pride in the school (often tied to athletics) that seems to be missing generally from smaller, urban law schools like Kent and Loyola. If you're a school spirit type, I'd recommend Wisconsin. From his experience it seems that UW has good placement at big firms in Chicago (and excellent placement at firms in Milwaukee).
I don't know as much about Loyola or Kent, although being located right in Chicago is convenient for on-campus interviewing, and if you can get more money out of them it might be your best move.