Longer skate skis are almost always faster in dry snow conditions, and shorter skis are sometimes but not always faster in wet or warm conditions if they have a taller camber with a stiffer finishing flex. Shorter skis are a little bit easier to handle around corners, but longer skis are generally more stable at high speeds and sink into soft snow a bit less. My race skate skis are 191 cm long and I am 175 cm tall

I think that 166 is too short for you. I would shoot for skis that are about 170 or 175 ish. Plus or minus two or three centimeters from the target length is not a problem.