Pugwash
Don't be put off by some of the negativity that's doing the rounds in NATS at the moment, they offer excellent training and far better salaries than the majority of regional airports who employ their own atcos, but like a lot of the outside world, things are changing within the organisation.
I won't go into that 'cos you can read all about it elsewhere in this forum, but in your position I'd still go for NATS training if you can.
It's bloody hard work and only a few get selected each year, fewer come out of the college fully qualified, you don't get a choice as to where you want to go and the validation process isn't exactly a stroll in the park - but then again it's not meant to be, only the best are required.
I now work at a regional airport where I am employed by the airport owners, I thoroughly enjoy the variation in the work, it's well paid, good roster and I work with some great people.
There are training opportunities outwith NATS, but they're difficult to come by and if you want to move on + upward within ATC and perhaps management, NATS is definately the option to choose as the pay generally matches the responsibility - unlike in non NATS organisations.
You face a couple of years of very hard work, after which you'll be in a job you'll probably never want to leave.