Personally, I wouldn't go for a snake that size for your kids to be around, something like a ball python which you mentioned you have experience keeping would be a much better choice.
I agree wholeheartedly with this. A snake that large could easily decide to constrict a child, even if you turned your head for a couple seconds it could have the chance to permanantly injure, if not kill the child. If you're strictly wanting pythons i'd go with one of the smaller ones, but you could always expand your horizions and maybe get a colubrid. I started in colubrids but I got a Chondro and soon i'll be looking at obtaining a boa of some sort.
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-Chris
The reason mainstream thought is thought of as a stream is because it's so shallow. -George Carlin
A fool doesn't learn. A smart man learns from his mistakes. A wise man learns from the mistakes of others. Which one are you?
My Website
N. American Rat/Corn snake care sheet I wrote
Information on substrates
Current snakes:
0.1 Licorice Stick Black Rat (Lola)
1.0 Black Rat (Frankie)
0.1 Texas Bairdi (Rosa)
0.1 Blue Beauty (Brunhilde)
1.0 Green Tree Python (Monty)