Pugwash,
If you're not sure whether this is the career for you, or what it's like to work for NATS, why not set up a couple of visits to NATS sites?
It will be beneficial if you get far enough in the application process, but may also help you decide if you think you'd fit in and be happy. From the ATCOs that I've met and chatted to, they're very upfront if you ask them what things are like (and perhaps won't sugar coat it like some recruitment bods).
Just a thought!