Dude. You are about to annoy most of the senior members that aren't already annoyed with you.
This isn't about a cheating mother. She isn't a cheating mother. She's a cheating wife. And that is why you are divorcing her. Not because she is a bad mom. You don't get to decide what she deserves and doesn't deserve. You are not her master. Slavery ended centuries ago. Don't like it? Go dig up former President Lincoln and have it out with him.
Now, mom has the children now. By that action alone, you are proclaiming she is a wonderful mother and you trust her. You couldn't proclaim that louder than if you held a 10 mile long parade with balloons, floats, dancing girls and a floating bar.
As for child support? What new math are you taking?? Do you know how much it actually costs to raise a child? Two? Three? Not no measly $500.00 dollars. You won't be saving ANYTHING raising the kids in your house. Because they grow, they eat, they lose things, they break things, they constantly want things. It NEVER ends. That $500 dollars is getting off cheap. I sincerely believe mom is not very bright for letting it get that low.