Sportlines will not help the harsh bumps. They are too low for stock struts imo and will be worse then stock on rough roads. Read some reviews on springs but you may just want to get wheels and leave the stock suspension for now, especially since our car doesnt have a ton of ground clearance to begin with.
For install check these DIY guides. The first one is the main guide and the second is a good shortcut so they go hand in hand
http://www.ft86club.com/forums/showthread.php?t=10842
http://www.ft86club.com/forums/showthread.php?t=32414