You also might want to do boxing with some groundwork like greco roman wrestling or BJJ. Kickboxing is very taxing to the body and is high impact if you get into it seriously. If you are out of shape then this might lead to frustrations and injuries. BJJ is low impact and you can tap anytime you feel like it. Also, if you are looking for something you can use for self defense, the learning curve for kickboxing is pretty long. An errant or halfhearted kick in a real fight will either get you hurt or sprawled on the ground. Boxing will give you fight awareness and remove some of your engagement jitters. BJJ will help you prevail when the inevitable happens.
"Speak LOUDEST, and carry the BIGGEST stick! Step on the little people, and then call their mothers UGLY!"