Cluster, repmgr, pgbouncer, pgpool, ha proxy, virtual IP, replication, failover and load balance

I would like to deploy load balance on Postgres master/slave(RW/R) servers and also use a virtual IP on this cluster

I currently have Postgres 9.4 using Repmgr for replication and manual failover to avoid split-brain problems and save a witness server. Also, there is Pgbouncer connection pooling working in session mode

So, what is recommended to use in my current environment?

Is Pgpool the best solution to use with Repmgr+Pgbouncer? In this case, should I replace Pgbouncer for Pgpool or use both? What about HA proxy?

I have never configured a virtual IP to cluster, should I use Keepalived, Heartbeat or any other solution?

Here is the image of what is in my mind: https://ibb.co/fZFebk
[cluster.jpg]

Thanks in advance for any help!