It would help to know a bit more about you. Where do you ski, what twins are you looking at?
Different manufacturers measure differently, which makes contact length different than the stated length on various skis.
One ski that comes to mind for you is the Head Wild One, which would probably be nice for someone with your stats in about a 161.
You may also like the Blizzard Titan eos in a 161, but that is a semi twin, not a true twin tip.
Hope this helps.