I have a 3gs 3.1.3 with old boot rom (non MC) which has never been jailbroken or unlocked and is locked to AT&T.

Could I have some advise please:

Is there an application that could jailbreak & unlock (without previously being activated)

Is it worth upgrading to 4 before attempting to jailbreak & unlock. Would there be many benefits

If activation is an issue is there a way to activate an AT&T card from the UK

Thanks in advance for any help