Hi there.
So, what you want is to migrate from phpBB to vBulleting forum script. However, I have a few questions:
1. Have you bought the vBulletin software?
2. What theme do you want to use?
3. When do you plan to start this project and when is the deadline, if there is one?
Anyways, feel free to hit me up so we can talk more about this. I am very responsive. All the best