Option two sounds like the far superior option to me.
There is absolutely no rush. I would take the time to try to get the best possible job you can, preferably in aviation. Save a bit of money and take a good few lessons to make sure you like it. Then when the time comes apply to tagged airline programmes. The FPP is very competitive and you will need some sound examples about specific times when you have shown the competencies that BA are looking for, as a school leaver you may find it harder to give an example that they deem acceptable, however it has been done.
Any flying course takes a certain level of maturity, some people have it at 18 whilst others don't. I've certainly seen a few fresh out of school people who I would never hire in a million years if I were a chief pilot, I have also seem some that I would... It is a very personal thing. I doubt I could have done it straight out of school.