Charity Events - Oganizing a long charity ride

Some friends wanted me to ride in the MS 150 and raise money but I have another cause that effects my family I want to raise money for. I want to organize a ride from Central PA to the Philly suburbs. I mapped it out to be 175 miles maybe a little longer. My first thought is that I would just ride from here to there and tell some people I was doing it and hope they would donate to my family's cause. Last year we did a walk which we rec'd an overwhelming amount of support for a different organization so I want to take it a little furhter and make it a sporting event I am actively involved in. Doing the walk was great but it's a walk and I would rather be riding my bike. Since I have been wanting to ride this trip I thought why not make it a charity event but I am not sure where to start. I am going to reach out to the foundation which I know doesn't have an event like this but I thought I would reach out to the biking community. I haven't found any resources on the internet about organizing a charity ride like this. There are loops but I wanted to make this a challenge and knowing my friends they could bet a certain amount against me finishing the ride(which would give me even more of an edge to finish it) and when I finish it they would donate the money to the organization. I was thinking of riding about 60-70 miles the first 2 days and then about 40 the last day to finish up. I think the logisitics would be the biggest hassle(where to stay, eat, etc.). I am not worry so much about mechinical break downs because they can be fixed so I was thinking of something self supported. I have read other comments on a thread lower down about starting small and going from there but I was interested in getting opinions from other folks if anyone had any about what I would like to try to do. Thanks.