Question on different ways to upgrade

[VH Freak]

I have a site that is currently running version 3.6.8 of Vbulletin. I need to upgrade because of spamming issues but I have a bunch of other mods installed. I also have vBadvanced CMPS and Photopost. I won't need either as I will be upgrading to version 4 of Vbulletin which has its own CMS. I would like to install version 4 and then import users and posts from my 3.6.8 forum instead of doing an upgrade. Is that possible? Would that be the right way of doing it? I just have a feeling that doing a straight upgrade with all my mods and changes won't work.

[OldSchoolDSL]

You themes / styles are the one thing you will not be able to keep.

3.x themes are not compatible or portable into 4.x

Many mods have updates & some 3.x mods do indeed work fine with 4.x, although it maybe wise to do some looking into.

Everything else you say you want to do... Is done through the normal upgrade anyways.