Vbulletin Upgrade from 3.8x to 4.x. + plugins install

I currently have a Vbulletin forum running under 3.8x and want to upgrade to vbulletin 4.x. Will like to have the same design and template, the upgrade will include some plugins migration and plus about 5-7 extra plugin mods installed. It will also involve then migrating the database to the new build. Its a huge database about 1.2 GB in size. Will send more details upon bidding.