Is it possible to make the east (or west) side of a BorderLayout to spread over the entire panel (include north/south)?
Just remove West and East from this panel and create a new "parent" panel:
JPanel newPanel = new JPanel();
newPanel.setLayout(new BorderLayout());
newPanel.add(westernPanel, BorderLayout.WEST);
newPanel.add(yourOldPanel, BorderLayout.CENTER);
newPanel.add(eastenPanel, BorderLayout.EAST);