Was doin a little surfin when I came across this:
http://www.stracing.com
click on the 06 catalog and they have suspension kits for the 6cyl & 8cyl
300Cs. The drop is 1.4" all around and the shocks can be purchased separate
and w/ springs. The front shocks feature a height adjustable spring seat.
Couldn't find any prices though, but they sound sweet.