Unless you are really really passionate about the topic (and are confident that it is the only topic that will interest you in economics), I would broaden the set of schools you are considering.
In the first couple years (and sometimes in later years!) of the PhD program, many people change their interests in response to the classes they are taking/seminars they are attending. Your interest in Post-Keynesian economics might be a function of the academic atmosphere of your current university, and once you leave, your interests might change. (I was really into general equilibrium theory at UCLA, because that is one of their strong points. Attending a university that pretty much shuns theoretical G.E. has certainly changed - at least temporarily - my research interests.)