No tool will help you here other than a find/replace with a lot of time changing property names by hand.
One possibility is to create a wrapper for DevDropDown to make it look like UltraDropDown ( properties you have used) and plugin that into your source [this may not be possible if the control is sealed etc.]:
public class myDropDown : DevDropDown
{
public string PropertyOfUltraDropDownWhichIsUsed {get;set;}
}