i saw someone dh racing a rst in a mountain biking mag. go figure.

the lowest marz for you can get is the mx comp, and that is 200(i think)
low end manitous are rumored to be bad forks.
i would go with the rock shox judy.

before doing anything, take a trip to a respectable lb. tell them your situation and they will most likely either back us up or give you another option.