I wouldn't put the two males and females in the same tank. I wouldn't even put the single pair in a 80 gal.

Putting the male in with the female for more than a few days can cause over-breeding and extra stress that can lead to off feed, an vent infection, or even over-stressed fatality. In a tank that big, you could hold one ball python in that tank and it would be over-stressed. You have to take into consideration that in the wild, they live in holes underground and like to feel secure. I had a baby ball python that wouldn't eat for a long time because it was in a 10 gallon. It has numerous hides and I didn't want to put her in a bin (she was a very nice display animal) and after I finally moved her to a 16 qt bin she started eating like no tomorrow.

No matter how long you keep snakes together with no conflict, there can always be a first time, and that first time can also be the last, for one or both of your snakes.

Another conflict would be you have two males in with two females, but the two males are different morphs, so you would have no idea what female bred with what male, how many times were they locked up, and when to look for ovulation and when will they drop eggs.

If I were you, I would first get a small rack system and then breed those snakes! they look amazing!