Honestly, go with the animal you like the best. If size matters, Jungles are probably on the shorter end of the snake size spectrum as far as carpet pythons go. Depending on which state you are in, NSW has a Code of Practice that calls for certain enclosure sizes (with arboreal species, the dimensions are counted from the back wall, not the floor).
The following only applies if you are in NSW: The shortest side of an enclosure shouldn't be shorter than 20% of the length of the snake residing in it. Therefore by that reckoning, you could house a snake up to 300cm long. However, taking into account the 100cm dimension mentioned, you would be able to legally house any class A, B or C adult python up to 300cm in length going by the NSW Code of Practice for Reptile Keeping. Although if the height is 60cm and you wish to house an arboreal species, the enclosure size would only be suitable for a class A or class B adult python. Jungles are class C while Coastals and Bredli are class D. For anything under 18 months old, that enclosure sounds like a great size, although if you are getting a hatchling, you'll likely end up starting out with a click clack style tub as large open areas may encourage a hatchling to go off its food as it may not feel secure. Placing plenty of hides may mitigate this.
I've got a Black and Gold Jungle and he's the calmest snake in the household (there's another B&G Jungle and an albino Darwin). However, he was also the most defensive hatchling out of the snakes we have to the point of it being a surprise if he didn't bite during a handling session. None of our snakes are aggresive. They have only bitten when acting in self defence, or if hungry. With the defensive bites, it was a matter of allowing the snake to get used to being handled, moving slowly, holding the snake with confidence, etc. With the feed response bites, upgrading food size solved that issue. Whichever snake you go for, be confident with handling the animal. Handle a few times a week to allow the python to adjust to you, maybe even leave an article of clothing with your scent in its enclosure. Chances are the snake will mellow with age, although there are snakes out there that are natural born demons regardless of species. All the best with whatever carpet you end up choosing.
Edit: Had a bit of a brain fart there, realised I have my math wrong. I was calculating the side wall dimensions of 60cm by 60cm for some odd reason and not the back wall dimensions of 100cm by 60cm. Technically, you could house a class C python in an enclosure of the mentioned size. Although a carpet python would appreciate a taller, rather than wider enclosure. Personally, I house mine in a enclosure that is 120cm high, 90cm long and 60cm deep.