Do you mean flip your stem to a lower position, or purchase a new stem? That bike should have a flip stem that allows you to change position without switching to a new one.
http://www.specialized.com/zz/en/bc/...jsp?spid=39270
The tech specs on that bike say that you do have the 4-position stem. I felt like I needed to be in a more crouched position to be comfortable and flipped mine down (I have the Ruby).