Maybe MBAProjectSearch.com or Craigslist?
Depending on where you live there may be some small business centers you can go to where you can work one-on-one with a biz counselor for free to get your biz plan done. That's what I would do.
Don't forget, your business plan is not only a document to be given out to raise money. In the beginning, the bus plan is an activity for yourself..so you really think about what you are attempting to do. It should make you think critically and as unbiased as possible. If you just make the bus. plan for other people you're missing out an a big opportunity.