@Override
		public Component getListCellRendererComponent(JList<? extends DataType> list,
				DataType value, int index, boolean isSelected, boolean cellHasFocus) {

			super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
			setIcon(DataTypeUtils.getIconForDataType(value, false));
			setVerticalAlignment(SwingConstants.TOP);

			return this;
		}
Remove any unwanted data type items, like arrays.
Ghidra/Features/Base/src/main/java/ghidra/app/util/datatype/DataTypeDropDownSelectionDataModel.java