The best "breed" to mate with a ball python is obviously another ball python. I have heard of breeding them to blood pythons to make something called "superballs" but If you are refering to what ball python morph would be good I would say it depends entirely on your budget and what you are looking to get If you have the money By all means I say a blue eyed luecy or a pied but again you are going to shell out a pretty penny especially for a breedable female male morphs tend to be cheaper so I would say but a normal female and a morph male but thats me as far as a wedsite goes check out www.bhbreptiles.com or just type in ball python morphs or breeders and you can comb through them