neither company would specifically is going to take care of importing content into the forum directly without some sort of added fee.
You can get us or vbulletin to do there install of the forum software. I can tell you we are cheaper on the install. You still need to purchase a license from them.
The photopost integrating into vb
would happen if you purchase an install from us.
Now the extra twist here is there would also be a small fee to download and import user data from photopost into vbulletin with there importer script which is another external application that needs to be downloaded and installed and run.
You can inquire through the contact us link for full pricing details.