Immigration from South Africa to South West Africa Now Namibia

My grand father Dirk Johannes Moller moved from Kakamas/Upington district in the early 1920/30 to Karasburg at that time Kalkfontein in the south of South west Africa /Namibia.He married Sophia Panizza.My grand father was a trades man building houses,dams etc.for as long as i can remember.My fathers name was Christiaan Deatlift Moller, he was a motor mechanic and married my mother Rhona Concordia Rex from Oudshoorn, South Africa.Out of that marrage 3 children was born.Randall Christopher(me) eldest,Desiree Cecelia Sylvia and Raymond James Moller.I would like to find the origins of my family from Europe.I think that my great great grand father is from Europe, immigrated in the 1800 to South Africa.