At present there is no combobox component in our MVC suite. We have logged this as a new feature in our database. We will implement this feature in any of our future releases.
There is DropDownList control in our MVC suite. Demo for the same is provided below
Also there is Autocomplete control, demo for the same is provided below.
Please check whether these components can help you to achive your requirement. To get started with our MVC components please refer the following link