Since xfinity stream isn't available on fire tv? How do I order a wireless tv box online?

This is a 2 part question post:

I've had the FireTV cube for a while now and have not been able to view xfinity content on it since I became an xfinity customer. My first attempt was to install the X1 stream app, but it was unavailable, and is apparently not in the roadmap to support. Ideally, this would be the best option to watch xfinity content, so that said, my first question is: any idea what the plan is to support amazon devices?

The second part question is; given that I was unable to install the stream app, I was looking into ordering the wireles box to at least watch xfinity content that way but there is no option at all online to order this. Any idea on how to order this device without having to physically visit a comcast store?