I have my iPhone Generation 1 jail broken and unlocked using ZiPhone (I know its not popular but I did not when I used it) and backed up on my PC which is where I have my music that is synched to the iPhone. Currently its working fine with no issues. That is why I did not bother to undo the ZiPhone unlcoking

I now want to upgrade to 2.0 and use pwnageTool 2.0.1 to unlock it. Since the PwnageTool is mac only, can I follow the following steps:

1. Upgrade iTunes on PC to 7.7 and do a complete backup on my PC. Do NOT install 2.0 on iPhone at this time.
2. Upgrade iTunes on my new Macbook Air to 7.7, connect to iPhone and update software to install 2.0
3. Download pwnageTool 2.0.1 on Macbook and jailbreak and unlock
4. Connect to PC and restore backup.

Will the end result of this give me an upgarded iPhone with 2.0 with all contents of my existing iPhone (i.e. music, contacts, notes, bookmarks, photos, calendar, SMS etc)?

I appreciate your responses and experiences.