It really depends on the specific statutes he has pled guilty under, and what sort of sentencing recommendations might have been made on his behalf (if any). His prior criminal record also plays a factor in the equation as do a number of other factors.
But, if he pled to PC 261, house arrest is almost certainly NOT going to happen. He might get "county prison" (i.e. sentenced to county jail to serve state time under AB 109), but house arrest would be largely unheard of ... though, under the right set of circumstances, I would not rule it entirely out. Strange things are happening these days.
Where he goes and what sort of visitation he might receive depends on factors we cannot possibly know. It is unlikely he will be sent more than a couple hundred miles from home, but that's a decision that others will make, not him.
Child custody will be a matter for the court to decide and will usually go to family members.

