c# ComboBox

I too busy to figure out what I need to override to make the combobox work the way I want it to. Winforms combobox. 1. I need a combo box that the drop down style set to dropdown. 2. I need a Read Only property to prevent users from adding items other than the autocomplete list. (behavior similar to dropdownlist). 3. I need the up down and left right keys to work, they only work when the style is set to dropdownlist. 4. I need charactercasing added to the control. 5. I need a max length added. 6. The autocomplete should highlight the remaining text when typing.