We don't have a cable box. Cable comes from wall directly to the tv. There is no cable connection on the tv.
Keep in mind that any scrambled channels will not work with any connection outside a device with a cable card from your provider or with their cable box. For internet access you don't need a cable box, it connects to your home network setup.
The tuner linked to above is an over the air tuner. You would need one that had a QAM tuner built it and yes you would not get as many channels as you would with a cable box.