The third link that you posted is for keepalived. keepalived uses LVS as the actual load balancer (which is what seesaw uses as well). So as long as you can set

The third link that you posted is for keepalived. keepalived uses LVS as the actual load balancer (which is what seesaw uses as well). So as long as you can setup seesaw to run a few scripts to inform DisitalOcean which droplet currently has the ip, then it should work fine. There is an example for keepalived in the link that you posted.