Robot controllers probably offer the quickest way to start working on your own robot. The robot controller usually package a microcontroller and a motor controller in a single product. The good thing is that you don't need to bother about hardware and software integration of both controllers. This is already done for you. You can be up and running quickly, concentrating on programming rather than on electronics.
On the other hand, you may still prefer to purchase separated products depending on the number and characteristics (current required, type) of your motors. This solution is more flexible but requires more electronic skills.