Billy -

Undocumented Pulsar feature that Jeff promises will break in the future, but you can use for now: pulsar:// URLs.

pulsar://com.xmradio.xmro?title=SIRIUS%20XM%20Hits%201&id=2

You can get these URLs by selecting "Record in Audio Hijack Pro", and then copying them out of the URL field that is displayed in AHP.

Then from AppleScript, something like: open location "pulsar://com.xmradio.xmro?title=SIRIUS%20XM%20Hits%201&id=2"

Will start playing that channel.