Mike;

My advise would not to be so hasty with decisions.
you havent actually stated what you like doing by you mentioned plumbing so i guess you want a "trade" as such. maybe have a look at http://www.olci.info/. you can fit training around your current job, i have a friend doing the electrical course at the moment.

whatever you do, dont jack in your current job, its very difficult out there at the moment.

end of last year i worked at Nationwide BS for 10 years and had a fairly good career earning not bad money, pension, health care etc etc. i was offered a new job earning more money and a car at a small firm i used to work for when i was 17, i took it and a few months later i was laid off! - i'm finding it very difficult to get a half decent job earning less, so my advise would be not to be hasty. Take your time

all the best