For statsd:

• I would use stretch
• We currently use https://github.com/hit9/statsd-proxy which has the big advantage of not requiring node
• We could just provide a 1:1 configuration to relay consistently to one upstream proxy
• We already have a deb package for this software, so the Dockerfile would be incredibly simple

For prometheus-statsd-exporter:

• It is a go software, so we might want to have a build container and copy the result to the final comtainer
• Upstream provides a Dockerfile we could use as a base https://github.com/prometheus/statsd_exporter/blob/master/Dockerfile
• It would be a good idea to check how hard is to build a stretch-only proper deb package. This is my preferred option.