So, good thing you asked. I just need one frame for each character. I will pay 3 dollars per character and the dimensions would be between 64x64 and 96x96.
To give you more details about the game, its sorta a minimalist card tactics game with a pixel art theme, and as a disclaimer it will not be for sale, your name will appear on my website and you will get full credit and publicity for your work.
Here is an example template image for the sprites:
