You're 6'1 and only 160lb - I think that's a big reason you haven't achieved much boob growth. I am 5'8 and a half, and over my first year of hrt I went from 193lbs to 130lbs and developed only mosquito bites for breasts - in fact, my breasts were bigger BEFORE hrt when I was heavier! Over the past six months I have made an effort to gain weight and have increased to 155lbs, and also incorporated micronized progesterone into my hrt regime. In the past six months my boob growth has been quite pleasing, to the point where I am now almost a B cup. Less pleasing is the fact that my arms have also gained an inch, but then there are still plenty of women with arms bigger than mine.
You might not want to hear this, but I think if you were to try gaining weight to perhaps 175lb you may experience boob growth. 175lb would still put you at a healthy weight for your height.
What I find interesting is that when I over-eat, like at Christmas or something, my boobs really start to itch the next day, and they look much bigger. Since my endo keeps my hormones levels at near-pregnancy levels, it's almost as if my body is saying "Wow! Here's some food, I'd better hold on to it so the baby can have some!"
I guess a lot of it depends on what type of woman you want to be as well. I would like to be super-skinny and waif-like but my frame won't support that, and I just end up looking ill when I get too light. If you are happy being skinny, then you should probably accept that you aren't going to get much breast growth, in which case implants would be the way to go. When I look around I rarely see skinny women who have decent-sized breasts.
