I think it's wonderful that you are going to help by donating! I, personlly, like the idea of giving to my local humane society. I do this because I am big on supporting the area that I live and also because the furkids at my local shelter are so near and dear to my heart....plus, our humane society relies solely on donations. You could even donate your time to visit a few of the furkids there....they love any affection that they can get!
You can't go wrong with whatever decision you make.