Please write up a blog when you have it fully working. I'm mostly interested in which STAT to USB cable you pick. Also power consumption in general :)
Look at the 'gluster' branch for my current active work on clustered persistent storage using SSDs and docker volume plugins.
I have setup quite a few GitHub projects for building / publishing multiarchitecture ARM compatible images of open source projects (Elasticsearch, Kibana, CAdvisor, etc). Check them out if interested in running common tools on RaspberryPis.