ELK Stack - Hardware set-up

Im new to the ELK stack - and in now getting ready to set-up a cluster with a total of 4.5tb and then expand later.

Can you please advise if this set-up works:
2xservers for elastic search
1server x logstach
1xserver for kibana

If you are looking for high availability you need at least 3 Elasticsearch nodes that are master-eligible. You may also want more than one Logstash node.

so you mean 3xservers for elastic search and 2xservers logstash and Kiabana - total of 7 servers - correct

That depends on what level of availability you require.

at the moment - it would be just a starting point and then we can add more node. So just to recap to start i can have

3x elastic search servers
1x logstash
1x kibana

Our maturity level is still at the begining