Thanks for your prompt answer!
ok, so i suppose in between O2 and Orange, it'd just be personal prefererance... and the content and the service would be nearly the same.
I will come back for more advice when anything arises, but in a meanwhile, I will go for whichever provider offers me the better deal!
It'd be easier if O2 does it so that I don't have to get the PAC etc...
Thanks so much for your help, MidnightDraven!! You are brilliant!