Wait a minute. If you're talking about doing "ethnographic research" through a graduate program in the U.S., then you're equally likely to be interested in a grad program in (cultural) anthropology as one in sociology, at least in terms of how those fields are taught in the U.S.

The schools you are listing (Berkeley, JHop, Wisconsin) are all top ranked, but remember that graduate programs in the U.S. are very department rather than school/university focused. Worry less about the university's general reputation and character than about the indivdual scholars, course offerings, research opportunities, and fellowship opportunities in your department. Talk to people in your field as your best source of advice, at least as far as the academic decisions go.

Other sources can provide useful information regarding the related contexts of your academic choices. Baltimore, Berkeley, and Madison are very different cities and each offers different life opportunities. But completing your degree will take only a few years, so you're looking for a relatively short-term academic placement. The quality and compatibility of the academic program with your academic/career goals should be paramount in your decision.