I think he means to replace the ShellListView by a Listbox descendant to cooperate with the ShellTreeView in the same way.
No, IFAIK such a ShellTreeView does not exist; you probably can rewrite it on the basis of the standard TShellTreeView and replace the Listview variable by a Listbox; and the Listbox must be modified as well, similar to the ShellListView. But all this is a lot of work... Why don't you like the ShellListView next to the TreeView?