One super awesome way is to embed an App in your Shop. With that, the App would be where you store the data. The App could then be setup to respond to an ajax call from the App Proxy. It would respond with JSON for example.
This is secure, and flexible.
Alternatively, since you can store JSON in a Metafield resource, you could store your array of data as JSON in a Shop Metafield. You could then use that in your theme too, anywhere you wanted to call it up. That is simpler for sure.
Man, that would be a great app. Just a simple array editor. Maybe JSON is my answer?
As an example, I have "reviews" that I use on my site. http://vibrolabs.com/reviews
It would be great to be able to store this data in an array and be able to call and sort right from a theme.