Here's a potential appointee if Coburn steps down early... OK House Speaker T.W. Shannon. It would make more leftist heads explode.
Speaker Shannon would be the obvious choice (a young, accomplished, popular conservative who would be unbeatable in the special election), and, as you said, he would make liberals’ heads explode (twice over, actually, since Shannon not only is African-American, he’s also a Native American (a registered member if the Chickasaw Nation)).