For vertical links, you have a couple options, depending on your budget. FenFab makes a very nice billet vertical link set for I believe around $350.
If you want something a bit on the cheaper side, $100 will get you the billet aluminum inserts that bolt into the factory vertical links and stiffen them up considerably. Steeda makes them and they have a very informative demostration video on their website. Not quite as good as the FenFab option but it comes close for less than a third of the price.