I would go for Wetware's idea. I have a SlingBox, that transmits to a SlingCatcher - which are no longer being sold. I bought the Catcher around 2009... I still remember telling Best Buy employee's what it was and what it does when it came out, as they had no idea, and instead of them getting me some questions answered for it, they phoned Sling directly and handed me the handset in store to talk to Sling!
Afterwards, I explained to the Best Buy employees exactly what the SlingCatcher does, and told them additional info I got from Sling about my questions. I was talking to (training) 5 or 6 of the Best Buy employees at once after I got off the phone with Sling! I'll never forget that. I never got compensated either by Best Buy for training their employees!
But since the SlingCatcher is no longer made, and the SlingPlayer is available on a multitude of devices now, including the Roku, you'll only need the SlingBox anyways.