Setup clean vB4 and import old database later?
 

Just wondering if it would be possible for me to setup a clean install of vB4 and work out my styles and layouts, then once all of this is working the way I want it, import all the data from my old vB3.8 database?

That is what you use a test site for. You set it all up and then export the styles/grids and then import them to the live site when you do the upgrade there.

Thanks Lynne, just want to make sure I have this right...

I can setup everything in a new database and forums, then simply export my styles and grids then import them in to my live database after I do the upgrade from 3.8 to 4.x?

You may export styles and grids, yes. You may not currently export data, like if you created a ton of sections and articles and such. But, you can see under the Styles & Templates area is Download/Upload Styles and under vBulletin CMS is Download/Upload Grids.