I'm working on a master's in a related field (neuroscience) now and applying to PhD programs in psychology and cognitive science. If you are dicey about getting an MA in Psychology from School X and a PhD from School Y, you could get the master's (and exposure, research experience, chance to decide whether you want to keep going) in another discipline that relates to your research interests and that is more inclined to accept and fund master's students.
I've also heard of people pursuing the master's-as-stepping-stone strategy and omitting the master's from their CV once they get the PhD, which I don't think is frowned upon professionally. So if you are concerned about future impressions, that's an option too.