Viamichelin.com shows three quite-different possible routes. The travel time with no stops, navigational errors, traffice tie-ups, etc., is estimated at 3 hr. 45 min. or more, which may be optimistic. The most central route takes you very near Arcos de la Frontera, which I think would make a nice 90-120 min. stop. Ronda takes considerably longer to appreciate, and it's not on any of the VM proposed routes, so your driving time would increase by more than half an hour if you visited Ronda.
Antequera is near both the northern route and the central route suggested by VM.
If you zoom way in on the VM map, the most scenic roads will be outlined in green.