I don't think anyone here can tell you what schools to aim for, because frankly I'm not aware of any admissions committees that make offers to students without research experience with a GPA below 3.7/4. Taking time off to work also doesn't play well because you lose out on potential academic reference letters -- profs tend to forget you after a few months of graduation.
HOWEVER
If you find a program you want to study in, and you make it clear on your CV through volunteer or work activities that you are seriously interested in that topic and are capable of doing the work, contact the prof you want to work with. The perceived caliber or the online ratings of the school that the prof works at aren't particularly important. Most of these guys just want to work with someone who they think will be able to produce good work that they can put their name on and who they know will be able to graduate. If you can convince somebody that that person is you, you're in.
I should mention that some profs don't like being contacted by potential students. Don't beat your head against the wall trying to get through to these people. Trust me, you probably don't want to work with them anyway.