I am a current AT&T customer. I do not have the ability to switch to a traditional iPhone plan. I must continue to use traditional data plans. If I purchase an unlocked/jailbroken iPhone 3Gs will it work for me? Will I be able to use the phone as if it were being used in the correct way, ie. iTunes, App Store, etc.? The phone is already jailbroken and unlocked will I have to do anything other than place my SIM card in the phone? I have purchased a phone from a different carrier before and had trouble with SMS and Voicemail, will this work properly? I am completely an amateur at this, will there be any hurdles that will be difficult for me to overcome? Thanks so much!