I would really recommend the taught MA. It only takes a year though, and the disadvantage there is that one barely has enough time to digest what one has learnt during that year. Nonetheless, taught MAs usually help students narrow down their research interests in order to come up with a very specific research proposal.
All Phds though, may have to apply as MRes students first before converting that into a Phd.
Usually, Phds take about 4 years. There are some opportunities to teach, but that is not usually the focus of the Phd. One is usually expected to focus on writing, conference presentations and one's research.
I hope that helps.