Rachel
try NATS by all means, whether as an ATSA (an increasingly rare species) or as a direct entrant ATCO on a NATS recruitment into CATC... the "College" at Bournemouth.
The NATS ATSA route is rare, the NATS ATCO route is more feasible, but takes a long time while waiting for interview, selection, recruitment, & a suitable course, and what are you going to do for living expenses in the mean time?.
Spoonbill & Niteflite are correct in that regionals are best for jobs in the short term, and this answers the living expenses question.
I was lucky enough to get a job with a regional (on £3500 p.a but it was 25 years ago) and get sponsored training for aerodrome, approach & approach radar...did my time to pay back the 'bond' and then jumped ship to the NATS money mine working at a band 5 (top pay) unit on circa £80K.. so it can happen.
As Punditgreen says, a lot of potential employers are looking to the future when they recruit today. It also means that you will get a lot of exposure to all aspects of ATC from signals & flight planning, to assisting in tower & radar to understanding the legal & regulatory side of life, especially if, God forbid, there's an 'incident'. There's also nothing to prevent you taking a job at a regional while still applying to NATS for either ATSA or trainee ATCO.
It all depends on who you start your career with, what they're prepared to do for you, & how hard you work to fulfill your aspirations.
From someone who went down this road & has had the best time ever over the last 25 years, best wishes to you whatever you do.
Tori