They absolutely need their own space. Cannibalism isn't common with ball pythons, but it's still a possibility, plus snakes really just want to be alone. Having two snakes in one enclosure stresses them out and may trigger illnesses and fasting. The tank you mentioned is certainly big enough; however, you will need two of those, one for each snake. You can also use tubs, they do hold humidity/temps better, but honestly, it's not hard to manage that in a tank once you get the hang of things. My BP is in a tank and I've never had any problems. Just make sure to cover most of the top with plexiglas and/or aluminum foil.