If your funding at UCLA is insufficient, I would focus on UCSD and MIT, as Vanderbilt is in an entirely different tier as far as rankings go (unless there is something specific about Vanderbilt that makes you believe it will be a far better fit than the other two, but that's not the sense I get from your post). If it were me, I would go to MIT, but that's because they have some fantastic people working on the topics and methodologies that I work on. I don't attend either, so I don't know a ton about their programs, but it should probably come down to a lot of factors very specific to you - where do you have a better potential advisor? Have you visited yet? Did you meet the professors with whom you imagine you will work and did you get along well? What kinds of topics within our very large subfield of CP interest you? Does either school seem to have more/better people working on your topic? Is there a senior professor at either location who seems particularly interested in you and your work (developing a close relationship early on with a senior professor who thinks highly of your work can open up a lot of doors for you)?
Perhaps if you share a bit more information about your interests you might be able to get some more useful assessments from people who know those programs particularly well.
One very minor point on location - one thing that I did not think about when I was choosing, but has turned out to be a nice benefit of attending a school in the northeast, is that it's not uncommon for a handful of top schools in the area to put together topic-specific conferences for their students and professors, which makes it much easier to network with top scholars beyond the faculty of your own university. I'm sure all universities hold some conferences, but my impression is that, due to the ease of travel between schools in the New England area, it happens a bit more frequently around here.
