It sounds like your primary goal is restoring your iPhone? I found an article here than can help you out with that:
iTunes: Restoring iOS software
Hope that helps,
To me, it sounds more like you either don't have a SIM in the phone, or it was hacked to unlock it.
A SIM is required for activation. If the phone was hacked to unlock it, you'll have to work with the carrier it's locked to and see if they will authorize a legitimate unlock. If they will not, the phone is a brick. It will not activate.