I have a PGCE in post compulsory education (PCET). I did mine part time over two years. Although the pace was quite leisurely, if you want to do it properly, you will have to dedicate a lot of hard work. You do not require an MA to study, just a BA. I certainly would not recommend engaging in any other study whilst completing it, especially a PhD. Most PhDs state that you should not even work for more than 5 hours per week.

A PGCE (PCET) will enable you to teach college students and adults. I’ve been teaching in colleges for 5 years, both teenagers and adults. That was enough for me. It’s very hard to get out of teaching into a new career, so I’m planning to study a PhD to move into new areas.