Im not a skiercross racer, but I have your same build and a pair of last years 191 Atomic GS skis. Race stock yadda yadda yadda. Theyre a lot of ski. If I were you, I would personally downsize to a 186. Throwing 191s around is not super fast nor is it super fun. But that is only if you plan on becoming a dedicated skiercross racer. If this is a one time thing, use em and have fun. Just a heads up, they require a lot of speed to get turning. Get a fast start.
191 Atomic GS (2010/2011 model)
165 Atomic SLs (2010/2011)
Suggestion, look around ski shops that sell race gear. Chances are, theyll have last years models for cheaper. Or look online.