Angel via Huatulco, one hour to the south. It has an international airport that makes access to the state of Oaxaca better than via Acapulco. I have heard that the Zapatista insurrections have spread from Chiapas state, to the south, into Oaxaca. Truth or rumor, I do not know, check with your country's embassy or consulate for travel advisories. Back to the buses.
Angel lies on the coast, west of the main hi way.
The town of Pochutla is the junction where you get off the Hi way and can catch a cab 10 minutes to Pto. Pochutla is where I catch the bus to Oaxaca city. This is a fabulous ride up over the mountains to a plateau where the state capitol is found, a beautiful Spanish colonial city about 400 years old. Well actually people have lived there for thousands. I have taken this route twice and love the ride up.