The Sebei live on the slopes of Mount Elgon in eastern Uganda. They number about 230,000 people and occupy the districts of Bukwa, Kapchorwa and Kween. Their territory borders the Republic of Kenya which is a home to more than five million Kalenjin, a large ethnic group to which the Sebei belongs. The Sebei, now known mainly as Sabiny, speak Kupsabiny, a Kalenjin dialect spoken by other smaller groups of Kalenjin stock around Mount Elgon. The Sebei and these smaller groups inhabiting the hills of Mount Elgon collectively are referred to as the Saboat.
Professor Walter Goldschmidt of UCLA has written extensively on the Sebei, and those who wish to know more about the Sebei can consult his works. There is no connection between the Sebei of Sudan and the Sebei of Uganda. The fact that they share a name is probably pure coincidence. (Please note that the writer of the above article about the Sebei or Sabiny of Uganda is a Sebei himself, so his facts are reliable).