C.S.
I don't usually do crowd funding sites - most of them take about 10% or more as their fee.
Our elementary school does an adopt a classroom program. We have local businesses adopt a classroom for $250.00 and then the company is mentioned four times in our quarterly newsletter along with a link to the businesses website. We are a very small public urban elementary but have managed to get each class (two classes per grade, K-5) adopted twice plus the specials (media, Spanish, art, PE and music). The parents are very enthusiastic about this program - some of them are small business owners who participate and others take it to their employer. Every type of business imaginable is represented: cleaning service, lawn service, cake pop company, a handyman, Chinese restaurant, and my company - a financial services firm.
Good luck - would be happy to send more info if you want to private message me your email address.
C.