another way is to create the sprites yourself via Paint Program. And also you can edit the sprite resources as well, and lastly if the resources don't satisfy you try mutations! Or use video game sprites... :) Hope it helps... :P
I have an Arcsoft Photo something. It has cool special effects but doesn't have some features Paint doesn't have (Like moving the object around when you pasted it). I think I can upload it if I kno how.