Oh boy what a trip! Well no better place to start China loads of paper work there are a few post a bout it use the search in the upper right of the screen for them was told $10,000 usd a few years back.
Russia you will want a good long visa with a option to get in and out as you see fit most are just one in one out and that will not do for you.
Vladivostoc to Alaska think you will need to go to Japan or South Korea first. May as well rid around when you are there. Then you will need to ride threw Canada to get lower 48.
I have said it before unless you NEED to get in to overland in to China and it may be easer to gust fly in and rent or buy a bike there then ride it about sell it and fly out as with much of South East Asia. the money you save can be better spent in SE Asia or South America $10,000 will get a lot of riding that a guided trip in China gust will not. I do not like the Idea of a guide telling me where to go and what to see But I still want to go to China and ride some day they will open it up and I can go but $10k to look at the back of some one just dose not feel right to me.
Now the bike you will need good going threw like strip it down and rebuild it may as well paint it when you have a bits off it. You do not need to but will get to know the bike a bit. anything that can go wrong will so new brakes and lines and stuff like that. Get all the numbers you can and see they mach up and know where they are.
you will need to get in touch with the consulate of each country you are going to ride in and start there paper work get a new passport and then get the visas.
remember half the junk 2x the money and time of what you think.
And go to HU meeting
http://www.horizonsunlimited.com/meetings/
You are in deep so this is the one you need to get to so register and pay now as in today this is the mother off all meeting you will have any and all of your questions answered by the people that have done what you are looking to do. AND tell you things that you have not even thought of. It is not far and will more than pay for it self on the trip.
UK Spring, 24-27 June.
Ripley, Derbyshire. Numbers limited. As usual, early birds are encouraged by a price break until end-December, so
register here now! This is the
Tenth Anniversary Event of HU Meetings, so be sure to be there, it's going to be amazing!