Хай!
В общем, интересует этот момент. Вообще, такое возможно? Подскажите в какую сторону лопатить?
void QComboBox::setView ( QAbstractItemView * itemView )
Sets the view to be used in the combobox popup to the given itemView. The combobox takes ownership of the view.
Note: If you want to use the convenience views (like QListWidget, QTableWidget or QTreeWidget), make sure to call setModel() on the combobox with the convenience widgets model before calling this function.