Only benchmarking with a realistic workload can say for sure, but my initial impression is that this sounds like a lot of power for the load you describe. Each of your SSD-based "hot" nodes already has enough storage for a year's worth of data at that rate. Do you need the "warm" tier at all? Do you need three data nodes or would two be enough?
You focussed on ingest load rather than search. Does this mean you expect the search load to be relatively light? If so, again, 3x coordinating nodes sounds excessive. Perhaps you can just search on the data nodes directly (via your load balancer)? Again, only benchmarking with a realistic workload can say for sure.
It sounds like you can put a load balancer between your Kibana nodes and the Elasticsearch nodes, although the recommended architecture is to point each Kibana at a single node.
They won't need much disk but will use a decent amount of RAM if you are going to hit them hard with lots of heavy aggregations or other expensive searches.