I have generally experience that a Masters is a good choice no matter what field you are in.

Dr or Phd need to be a careful decison as you are essentially studying a very specific process which doesn't lend itself to Industry and more likely to be as precursor to going into Academia. I knew a guy at work who dropped his Dr title from his bus cards etc becuase he didn't want to be labled as a person who couldn't do anything apart from his doctorate.

Great minds think alike, but fools seldom differ. (English Proverb)