Volkl Tigersharks in New England or not?

Hi,
I am fairly new to skiing, this is going to be my 4th season. I am 33, 5.7 180lb. I consider myself a good intermediate hoping to go to advanced intermediate, not sure I will ever be an expert.
I am considering buying Volkl Tigersharks 10ft. Previously I skied on Atomics Beta V 170s. I think I could handle something faster.
I am not sure if I should go with 168 or 161 to compensate for speed and to be able to relax more, or maybe this is going to be too much of a ski for me regardless of the lenght?
Any advise is greatly appreciated,
Thanks