You dont need them for the Front, only the rear.
Normally no one will tell you need to buy these arms when you buy Lowering springs.. I think just about every car in the world would need to replace some suspension part to get the correct settings.
They cost about 215 on ebay from our vendors store
http://cgi.ebay.com/ebaymotors/Porsche-986-Boxster-97-05-Adjustable-Rear-Toe-Arms_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el126 2QQcategoryZ33583QQihZ020QQitemZ300200870735QQtcZp hoto