Basicly any Elgato should do the trick, just be aware that when attaching to a cable/sat box, unless you have an IR blaster type device in play, you are going to be using the cable/sat remote to change channels and set timers.
Used to have a Hybrid plugged in to a mini then imac before the "plug in the wall and watch" cable went away. I keep checking it to see if we have any OTA HD channels, but am usually disappointed. I plug it in every now and then to rip VHS when I know I'm going to be away from the computer a while