Here is an article from Maxim describing the differences between DACs and digital potentiometers. The article explains the characteristics and advantages of each, giving you a better idea of what you may need for your project.
This application note compares digital to analog converters (DACs) to digital potentiometers. Traditionally digital potentiometers were meant to replace simple mechanical pots. With recent increases in resolution and additional features, digital potentiometers can also be used in some traditional DAC sockets. Similarly, traditional DAC packages were too big and too costly to compete against digital potentiometers. However, DAC pricing and package size have reduced significantly, so in some sockets a DAC or digital potentiometer can be used.