I think that's a wonderful idea! I nees to ask, tho- what Humane Society? I'd personally stay away from the Humane Society of the Untied States (HSUS). They are in cahoots with PETA. This is just the most current article about them:
You might want to look into doing the fundraiser to support a local rescue or shelter.
I think there was a fundraiser like this out on Long Island a couple of years ago. I'll get a hold of someone who would know and direct them here.