You can use IP.Converge to integrate XenForo with IP.Content.
IP.Content is far superior to vbCMS.
Based upon my own personal experience and opinion....
Besides the fact that you would 1st need to buy IPB as IP Content is
not sold separately and you can't install IP Content without first installing IPB, as they also would
not work separately. Then take into account (last I knew) that IP Converge isn't being further developed (last I knew).
Now assuming the extra cost, resources, and development doesn't scare you away from that idea. You'd have to take into account the company, Invision Power Services Inc, unethical, unprofessional, immoral, and arguably illegal business practices (speaking from my own person experience and opinion).
You're much better off from a business point of view, short term & long term cost, plus from a resources point of view; to simply using XenForo with XenPorta or Word Press or Sub Dreamer or even the current Joomla plug-in rumored to be in development.