U - All of it, you should not be thinking about recon at all. If you are thinking about recon then you will allow your desire to recon over shadow what is in your best financial interests.
When my XW moved out we came to a 50-50 custody arrangement along with a financial agreement that was essentially accepted by the judge as well. I was lucky that we did not have to put any formal documentation in place as we both honored what we discussed.
Don't move out without something formal in place. I can tell you with three small kids and you being the bread winner you will more than likely be paying alimony and obvious child support. It will be greatly reduced, probably in half, if you get 50/50.
