@”Кирилл Александрос” Here are the names of the Carantanian dukes you might like. You can find more Slavic names online but I haven’t seen these mentioned yet.
Valuk (or Vladuk, Vladun), Borut, Gorazd, Hotimir (also latinised as Kajtimar), Valtunk (could be of germanic origin or a version of Vladan, Volkun or Vladuh, also written as Valhun/Valjhun), Pribislav, Semik (short for Semislav), Stojmir. If you like oxymorons then Vojnomir is for you.
I like Bogomila for girls. Some have used Kajtimara in the past, female version of Kajtimar (not pure Slavic, but it is derived from a Slavic name).