Kafka Cluster solution deploys multiple VMs for Kafka and Zookeeper in clustered mode while
Kafka Certified by Bitnami is an all-in-one VM which contains all the required services on a single VM.
On the first solution, in addition to multiple VMs, a new isolated network is also created and as you are mentioning, it doesn't support to specify an existing network.
Does the solution
Kafka Certified by Bitnami suit your needs?