You never indicated how much experience with riding and/or touring you have. Also, you indicated you have "support" but that could be financial, vehicle, press/PR, etc.
With MANY years of experience, you could probably use a regular AAA road map and have a good idea of a route but it would not be the shortest as-the-crow-flies but shortest as a bike rides.
You could perhaps look at the archives of cross state bike routes. For instance, Oklahoma, KS, GA, etc. have annual rides across the state. However, most bypass the large cities on purpose.
Additionally, 650 a week while touring for 10 straight weeks would be very tiring. And that is assuming the 6500 miles was a realistic distance, not a Mapquest distance. 650 miles a week is almost a century a day plus I assume you have "downtime" for the fundraising, rest day (yes your body will require rest days), etc.
This would NOT be a fun trip at all even if you had total support, i.e. someone doing all work and you just ride and smile for cameras. Are you hoteling it at least??
I would strongly recommend either lengthening your time, or cutting some states.
I don't want to dissuade you from your goal but a goal needs to be obtainable
Happy trails and may the wind be at your back!