Malifaux minis has a couple of good witches. Google malifaux zoraida, one standing, one crouching over a cauldron. Also castle ravenloft has a good hag miniature you may be able to pick up on eBay if you don't want the entire game. They're in my plog though with some conversion.
Soul seekers witches are indeed awesome, with amazing paint jobs. They are from Enigma minis I believe