What kind of cow?

We are talking about getting us two baby cows soon or later after we put new fence around our 18 acres of property. What kind of cow is best for being pet and friendly and like to get around my children where they can go in the pasture than being afriad they would chase them something like that. We would love to get a horse but know we won't have lots of time to ride.. so we decide to get us few cow. We would like to get baby first to feed and raise so they would get know us and become our pet lol..

Any suggestion will be appreciate. Thanks..
Tricia