I've never kept live plants in my reptile cages, but I'll go out on a limb and share a thought with you...

Snakes pee and poo where ever they explode and sooner or later it will be on your plant I've had my big spider girl pee and poo in her water bowl. I've had them pee and poo in all different places all over the cages. I've had them 'tail paint' their poo everywhere Also, my snakes in cages are all about 1200g and they cruise around at night all over everything!!

I'm guessing that your plants would be short lived with either being smooshed by a heavy snake or pee'd or poo'd on

As for a large water bowl, I have one in each of the cages for a humidity bump. I have yet to see a snake go into it