Importing it legally under federal/EPA regulations to drive around as a tourist vs getting it legal to register and titled in any given state may be two different things, almost certainly handled by separate parties.
For importing, I can't recommend anything other than a dedicated vehicle shipping company. Working with a vehicle specialist as suggested above doesn't make much sense to me because they don't run containers, warehouses, or work with expediters. All they are going to do is find someone else and pay them to do the actual work and pocket a commission for themselves.
I had great success shipping a BMW motorcycle to Germany and back using West Coast Shipping which operates two warehouses in the US. Their primary business appears to be moving rare and classic cars, but offered the best rates I could find in both directions. Their partner in Europe was Marlog Car Handling BV when I did my shipment late last year.