I can promise you more headaches. We are on a two Years scheduling for that trip from Germany. Finely we start 9th of May on two bikes.
Started up with 12 Riders. Eight of them gave up. Two Guys and there Ladies come in via Vancouver. On of them bought a bike in Seattle but gave the contract back due to some problems with registration and they other couldn't find the right one so they use a Camper.
The last two my friend and my self including our wifes we start from San Francisco. I bought a bike close to San Francisco and my fried has hired a Harley just Down Town San Francisco.
Our first schedule was take our bike over on a ship or on a flight, to expensive.
Second we gonna buy some bikes over there and take them back, also quite expensive and some problems with registration without an US Passport
Third we rent some.
OK it turned out this way, I bought one because my son is living in Florida and I keep the bike over there for next Years to use it when Im in the states. My friend rented one because it is the easiest way.
I would recommend rent a bike over there.
Your waiting time to get the bike over there and back is much to long. If it is fast 2 - 3 weeks each way by ship to the east coast, west coast take even longer.
Take a flight, is to expensive up to 2000,- Euro each way.
On a rental you have everything included if you strand they will pick you up. You have not to hire them for the Trip you rent the bike and do the trip on your own.
Hope I could help you a little