RAF career = varied, lots of fun, lots of fantastic similarly-minded colleagues, lots of time away (depending on aircraft type, etc), some risk of death, reasonable pay.
Commercial career = not so varied, fun (at times), some similarly minded colleagues (but you might only meet up with them every few months!), more time at home (depending on airline!), very little risk of death, much better pay (& discounted travel?).
If age & circumstances permit, go RAF first, then commercial later. If you want the money, then the RAF just can't compete. Good luck for whichever one you go for - if it's the RAF, look at
http://www.timc.clara.net/raf.htm
for OASC tips for when you go!