Which helm repo?

https://github.com/helm/charts/tree/master/stable/elasticsearch - "public helm chart" repo

they both look to be actively maintained. The "public helm chart" repo seems to have more things in it, master & data nodes, etc.

Great question! I would definitely recommend using the charts at https://github.com/elastic/helm-charts. The stable/elasticsearch chart is actually in the process of being deprecated in favor of the official Elastic chart. You can see the pre-deprecation notice (which was merged yesterday) in the readme of the /stable Elasticsearch chart. The Elasticsearch chart in the Helm repo will not be updated beyond version 6.x.

We've been working very closely with the community maintainers since Kubecon Seattle (in December of last year) to ensure that the migration path between the charts is well defined and that the functionality of the Elastic chart meets the needs of community chart users. We're also encouraging users to open issues on the Elastic repo for any functionality they would like to see in the Elasticsearch chart if they feel something is missing.

I suspect that the multi example in the Elastic Elasticsearch chart may provide what you're looking for if you are interested in configuring dedicated node types. If not, please do open an issue outlining the functionality you see as missing and we'll take a look at getting it added!