Replying to Can't decide on which pair of skis

Hey, this is my first post, I'm having a hard time deciding which pair I should get.

First, an intro.  I've been skiing since 4 (I'm 20 now), but I just got back into skiing after 4 years without.  Back then I only did groomers, blues/blacks and whatnot, but now I'd like to try a bit of everything (park, powder, anything).  This season I had to ski on my brother's planks cause mine were juniors from way back.  I pushed those quite hard, they were unstable, kept chattering and trying to overturn me when I was going through the crud.

I ski quite hard, pretty small at 5'6" 120lbs.

Here's the dilemma:  I originally wanted to get the 2009 4frnt MSP's through the college deal, which should cost me around $420, but since I'm getting all new gear for next season, I'd like to keep the costs down.  The alternative right now is the Line Prophet 90s.  I've found a deal for a 165cm, which should be about $100 cheaper than the 172cm.  I know twins ski shorter than traditional skis because of the tail, so something longer would be best...guh my brains are turning into juice just by thinking about this.

Please advise.