Well your not going to be able to say import things as there are no import scripts for such a thing
What is not clear to me here is where do all your users exist on this site that needs to be upgraded?
vb or postnuke?
I guess knowing what can and can not be done depends on what is going on in your site.
I will quote based on thinking these alledged users exist in vbulletin. This is just to upgrade these two applications here on the main site it has nothing to do with any beta site.
We can upgrade your
vb and photopost for the following fees.
We offer a custom forum install/upgrade for 70.00 which is almost half of what vbulletin offers to do their install/upgrade.
We can reinstall/upgrade your old photopost to operate with your new
vb 3.7 forum for an install fee which is 59.00 and can be purchased off our main site.
In the comments of that order meantion this thread and you want a forum install.