Pretty much all lips need the front splitters. I just put one on my car a few weeks ago, after installing the splitters. The official name appears to be "corner splitter" although there's probably a more technical name that is used in the real parts list.

Subaru Genuine Parts has them on their site. You need to break off the tabs on the inside (near the lip that sticks out) of the splitter and cut some holes in your bumper (in the seam) but its not hard. I did it all in aboot 30 minutes.

If you need help with the install let me know.