I am in the year of Aveilus for my mother, my Father’s Z”L yortziet is coming up when I daven before the amud and say Kaddish do I say Kaddish for both of my parents or better to say Kaddish for my father and appoint someone else to say the Kaddish for my mother.
You should say the kaddish, better than hiring someone else to say it. This is because when a child says kaddish for the parent it is a bigger zechus for your parent, because thier child is being mekadesh shem shomayim in public. When a child says kaddish even for both parents at the same time it goes for both of them, similar to he idea of “ner l’echad ner l’meah” , a candle lights up for one person the same as for a hundred. Therefore daven and say the kaddeishim regular.
Be’er Hetiv O:CH 132-5 quoting Knesses Yecheskel, Birkas Reuven Shlomo 5-67. As a side point his would not apply to a person being paid to say kaddish and thyen has to say kaddish for a parent.