I compared the prices between EPN and ASTAC. EPN is nearly double than ASTAC. I don't know why!
Anyway, I received some suggestions that OJTI doesn't raise the chance to get ATCO job abroad. So, I found out that my background, base experience & qualifications are the most important points they consider during the process!
As I got from comments, I should pass initial ATC training & a course like Area Surveillance course in an institute like ASTAC. But, the problem is after completion the course, NATS won't allow me to proceed with the schedule and complete the OJT in UK!
Any other solution?