:D
Hi
The legal age to hold an A & C used to be 21 , not sure what it is these days. (Also you needed three years experience of working on aircraft to qualify to sit the exams.)
I got my engine licence in the last year of my apprenticeship and was frozen until I was 21 and got the airframe when I was 21.
I would think you'd probably need 3 years min to get the licences, unless anyone can comment further.
Also if you do get an apprenticeship with a good company, they'll probably send you to college to get further qualifications anyway. (I got a BTEC ONC and then an HNC in aeronautical engineering through my company, although the HNC was voluntary. (They still paid for it and gave release in order to do it.)) I would do the apprencticeship. You will get qualified anyway and if you're interested in aviation why not? I started that way and fly them now.
Cheers

Please do yourself a favour and make sure you complete your A levels. This is really important because it a) keeps your options open and b) allows you entry to degree courses etc later if you should so choose. Regardless of some of the comments, having the best qualification allows you greater choice, even if you have to defer some of your aspirations for a year or so. Good luck.

There have been a lot of comments so far about the actual qualifications you could study for and one thing not mentioned so far is their transferability (is that a real word?). A levels are a universally recognised qualification that can open a lot of doors to courses, jobs etc. If you take the time to study and gain a JAA licence and a few years down the line decide to change tack, there are not that many choices - especially without other qualifications to add in. The licence has no direct relationship to, say a degree or HND or whatever, and most people outside of the industry even know it exists.
It is a lot of work to get a licence, which ever way you choose to do it and , as with all industries, there are no guarantees of a job at the end, but with licenced engineers becoming more sought after I would think you would find a job anywhere, if you were prepared to look for one - granted it may not be a first choice one, but it's an ever changing area to work in.
You could also look into doing a course such as the ones run by Brunell in Bristol.
I did an apprenticeship in the RAF and after leaving studied for my CAA licences myself. Took me nearly 3 years to get the first one - mainly due to laziness. If you really want to gat into this job, I would reccomend getting licenced as soon as possible for job security as well as a wider choice of jobs. Having said that, there are jobs for unlicenced fitters, who can earn a very good wage as contractors, but you would need a trade apprenticeship behind you and be prepared for a varied work schedule.
If this is the job you want to do, then go for it. I wouldn't try and put anyone off. Best of luck

:)