HEDP,
Left the green machine a couple of years ago and have managed to have a go at pretty much everything since, though not abroad yet.
The police/hems is ok, can be exciting at times but generally lots of sitting around waiting for something to happen playing computer solitaire, the money is not brilliant either and you can end up working long weeks. The good side of Police/Hems is there are units all over the country to choose from you will however have to crowbar somebody out to get a seat. Pipelines are hard work and not very well paid but you generally work a 3 day week in good weather, longer if bad. Instructing, dissmal. My personnal choice is offshore, good money, more time off than you know what to do with, big aircraft and bringing in new stuff in some companies. The work is straight forward as well, go to work an hour before the flight, fly, go home.
Loads to choose from, one tip keep all the c*£p off your CV, nobody cares if you won this, that or the other in tiddlywinks.
Good Luck