Child Surport

Finally, we both agreed to go separate ways. But child custody will be a tough fight. Just try to get a feeling of financial impact. Thanks for any help.
We live in California. I make 120k a year, and she makes 80k. Two kids at 5 and 8. Have a house almost paid off, and some stocks.
If she gets the children (which is likely), how much I should pay for child surport (roughly)? Do I need to pay her as well? Does she get the house or it will be sold (it worths much more than the stocks we have due to the crazy market)? Oh, how my stock options will be expensed? :)