I get my sprites from Spriter's Resource, @Swampert "Beef Cake" Poke . You can find really good sprite sheets there. BTW, the pose for the one on the right was made by me by altering the original sprite.
do you want in game sprites? ill give you a link to where i got mine, but make sure you have an anti virus, that may be the only reason i don't have a virus, i can't guaranty a virus free experience. If you are paranoid of viruses, just don't as this is not an official source DOWNLOAD AT YOUR OWN RISK