The courts have established custody in 2004 giving myself full residency of the children and joint custody with the father. There father is court ordered to child support. Since there father has not had contact with eather child or myself since 2007 and has not paid child support since 2008. Can I file for full custody of the children again? Should I file for abandenment so he looses all parental right to the children?

You can't file for anything that will take away his rights to the children. The only think that can do that is an adoption by your spouse. You can however, file for a change is custody, using abandonment as the reason, so he doesn't just show up and try to take the children for visitation.