2 separate enclosures at all times. They can be as simple as tubs, but they must be separate.

As for sexing, there's another method called 'popping' that experienced keepers can do. It doesn't use any tools, but you have to know what you're doing. It can be taught, however.

And, as far as the enclosures go, remember that you can build a rack or two stacking display enclosures to save space and money. There are lots of ways to reduce money and space use for multiple snakes...and most of us here have mastered them.