I hover between 5'7" and 5'8" (mornings I tend to be taller), and I'm going for anywhere between 115-128ish. Sounds really really low but it was recommended to me, plus I am definitely pear shaped. Very small on top, and very big on the bottom. I was around 135 in December-January (stupid holidays
), and I couldn't tell any difference between that and where I am now (about 10lb heavier), so I figure the low 120s will be just right.
It's more trial and error, as everyone is built differently and everyone looks different at a certain weight. Someone who is 5'8" and 165lb could look heavy. Someone else who weighs that could look perfectly toned and healthy. I say go for your goal of 165, and if you like where you are, there you go. If not, just lower it by about 10lb.