Hi ricko,
Well the first thing to do is have a trial lesson at your local school and see how you like it. If I were you I would stay at school and get into university, get a degree, it will always be there to fall back on.
Then save like mad, if you can.
You will need a Class 1 Medical to hold a CPL, your inital has to be done by the CAA at Gatwick. It is upto you when to do this, but if you are going to do your PPL I would get it done then. As for eyesight the CAA link regarding this is:
http://www.caa.co.uk/docs/49/SRG_MED...s(June-06).pdf
Then it is only a matter of what type of training you do, I would go modular rather than intergrated, because of the cost saving, (Modular approx £30, 35K and intergrated £65K+ don't forget living expenses as well though.)
Hope this helps.
Frank