I second your recommendation of the Roku box. I’d add that you don’t necessarily require a TV with an HDMI input to use one. Roku makes three models, and the basic models work fine with TV’s that have regular A/V inputs. You just won’t get a true high-definition picture.
Another interesting thing about my Roku is its snappy command response speed. I also have a Vizio wi-fi TV and my Roku runs rings around it as far as executing commands from the remote. It also works with my Logitech Harmony 600 remote.