A few questions on purchasing

[Armchairfighter]

Hello everyone,

I currently have a forum that is with IPB. I have grown tired of using them and everyone is asking to move to vbulletin anyway, so I am in the process of making the move. Here are a few questions I have.

1. I see I can purchase the Vbulletin Publishing Suite or the Vbulletin Forum License. What is the difference?

2. Is there a chat mod I can install on the forum so we can have a chatroom attached?

3. Is there any costs to move all of my threads and posts over from IPB?

4. About how long would my forum be down during a transfer like that?

5. I pay $20 a month for IPB to host my forum. What is Vbulletins costs?

Thanks in advance.