Check out Greg Paul's incredible overlanding adventures on Facebook or his website. This summer he took a group on a 63 day tour from Vladivastock across Russia to London. This is the same company, in the same trucks that I did the Dakar Rally with this past spring. After the Dakar he took a group down to Ushuaia then north through Chile...before shipping the Cruisers to Russia! Insane! Now the Cruisers are on their way back to South America to do another Dakar!
Greg does everything from ride along to self drive tours. Build your own 4x4 and he arranges everything...vehicle shipping, route, hotel rooms and meals.
I highly recommend Greg and his company, Rally Tours NZ.