By the notice on your stem it simply means no dedicated fulltime DH or XC. Nowadays this includes drops, jumps, rocks, roots, fast speeds, big front end hits (which could under the original build or that stem) break. They say this for warranty, and liability issues. Not all manufactured bikes as I am sure you know are meant to be ridden hard and put up wet on a full time basis.
Anywho Dirtbikedude's advice is great. I will suggest and I am being biased, that I have a set of Wellgo WPD 800's on closeout if you are interested. Check my list. There are other things there as well.