" I was brought up Catholic, and DH was brought up an aethiest, so none of the Catholic schools would take him, "
I work in a Catholic school and this is not entirely true - but is a little. Catholic schools have to meet a certain quota from their Diocesan office of at least 75% of the students being Catholic. One of the criteria's on enrolling your child is that they are Catholic and/or will live in a Christian manner. If there are not enough Catholic children they will enrol non-catholic children. If your first child is enrolled the schools will automatically accept all your other children - whether or not they are christened. They do not have to enrol your child but do on occasion.
Good luck!