That must have been a short marriage, but already have kids? 
I’m not judging. Things happen. We also had two kids in the first two years after marriage and I am to about to get APRC in February. Still happily married.
How long out to APRC? I would recommend to postpone the divorce until you have it. Your wife can not force you to sign the divorce papers.
The custody and visitation right can be very tricky for foreigners. If your wife will get full custody, you can not use JFRV based on your kids. Just protect yourself.
Other possibility for residency might be the Gold Card if you qualify.