Hey Rob,
If you're absolutely sure you want to become a pilot then well done to you sir as you know by 16 what it took me 25 years to figure out, so therefor you have a 9 year head start on me!!
Age will probably hinder you a little at the start until you build up a name for yourself. But by the time you have 1000-1500 hours you'll probably be unstoppable!
The only unique advice I can give you that you probably won't see in other posts is, if you decide to do your training in the US I would recommend looking for a school that offers a J1 visa for your training not an M1(unfortunately I went with the M1). That way you can work as an instructor building hours for a year or so in that school after you qualify as a CFI. Somewhere like Bristow Academy that also offers the JAA course also, so that you can kill 2 birds with 1 stone. I didn't go there myself but I've heard good things from people who did and are now working for them in the UK.
If you did choose to train in the US, go for somewhere like California over Florida, as the weather will be more stable there. Also Cali has better terrain for helicopter flight training.
Thats about the best advice I can give you right now as thats the area that I know. I done the US thing because the costs were alot less.
Cheers,
Darren.