And it depends because of how the person skis.
Narrower is fine for "classic" ski touring, shorter radius, slower turns.
Fatter, stiffer and longer works for faster, larger radius turns in variable conditions.
For you checkout something ~100mm at the waist and maybe 170cm-180cm long? Or fuckit - pickup some K2 shukshans when they appear on Steepandcheap.com today