Kops version 1.6.2 and above now officially includes kube-router integration.
Please follow the instruction at https://github.com/kubernetes/kops/blob/master/docs/networking.md#kube-router-example-for-cni-ipvs-based-service-proxy-and-network-policy-enforcer to provision a Kubernetes cluster with Kube-router.
Uses the kops latest version binaries which has the kube-router support.