Creating a Multiuser Site for a NonProfit

Hi,

I am seeking advice on the best way to build a site for my nonprofit. It is currently on a basic host, but they do not provide the functionality I need. From what I have read, Multisite and BuddyPress combined might give me what I need. I am asking for help to determine if this is the case.

The nonprofits value is as a place for people to register and leverage fundraising tools to raise money for their cause, so they can focus on what they are trying to accomplish, and not on trying to figure out how to fundraise. (pennyamile.org)

So, here are the requirements:

1) Needs a central landing site for all visitors, whether they be participants or sponsors
2) People participating with the nonprofit need to be able to register as users
3) When the participants register, they will be provided a site template for them to create their own sub-site for communications and fundraising – blog, picture posting, etc
4) Want to collect donations for their fundraising on both the central site and on sub sites (need to track donations to the registered user and their cause)

SO, I need a multiuser site with a central admin for all sites, and individual sites (template based) for all people who come and register to raise funds for their cause.

I REALLY appreciate the help and advice in advance. I am a little stuck on the best way to proceed.

Thank you,
Kyle