KnitKing is just another brand name for Japanese knitting machines manufactured by Brother Co.
Below is the list of models I’ve seen branded as KnitKing. If you do not see a machine model number you are interested in, check out the Brother Knitting Machines page as the model numbers are often interchangeable.
Simple Seven, mid-gauge, plastic bed, basic/manual
KnitKing KH830, standard-gauge, punchcards
KnitKing KH881, standard-gauge, punchcards, built-in knit leader
KnitKing III, standard-gauge, electronic
KnitKing IV, standard-gauge, electronic
KnitKing KH260, bulky, punchcards