I am interested so count me in. Have a CB750 that is kitted out ready to go. I was planning on doing this trip as well. Another thought I had was South Africa to Norway (arctic circle) - its about 25,000 miles I think and similar length of time.
PM you with my email address.
As for budget in the US or anywhere else for that matter you need to factor in not just food and accommodation (the cheapest part) but also gas (expensive part especially outside the US), maintenance items (tires, chains, oil, spare parts, shipping charges, emergency funds when things dont go as planned etc etc). And then their is the sightseeing costs (otherwise whats the point of traveling) such as entrance fees (museums, parks, castles, toll roads, visa fees, insurance for each country) and other misc. fees that are bound to crop up. It dosent have to be wildly extravagent and can be as bare boned as you like (e.g. climber featured last night on "60 Minutes" said he can survive in the US on $1000/month by living out of his van).
cheers
Andy