Buying My First Pair of Skis

Hello, I have been looking into buying my first pair of skis and was looking for some help deciding. Thanks!

First, here is some information that might help you guys help me:

LOCATION: West Coast (California), both Mammoth and some of the SoCal mountains
HEIGHT/AGE/WEIGHT: 5'9", 16 years old, and 155ish pounds
ABILITY LEVEL: Intermediate/Advanced(?), can ski blacks with no problems, moguls can give me some trouble, love skiing the park but not that great :P
BUDGET: Preferably under $500 without bindings, obviously the cheaper the better
WHAT I'M LOOKING FOR: A twin-tip ski that can take me through most of the mountain, I spend about 40% on groomers, 40% in the park, and 20% off-piste, as close to a one-ski quiver as possible

Notes:
I've been doing some research (shown in the spreadsheet that hopefully was attached to this post. One of my largest questions is in relation to underfoot width. I would like substantial width so that my off-piste adventures go smoothly, but as most of my time is spent in the park and on groomers, I don't know if I'll need that much width. Any suggestions? Also, if there are any skis that you think would fit the bill that aren't listed, please give me a heads up so I can look into them.

Thanks!