When I was younger, it didn't really matter to me if the guy was thin...but then again, times were different then. Now, I prefer a man with a little more meat on him--I think it is more sexually attractive. I am not in your target age group but most of the younger women I know would probably also prefer the average looking guy with the toned body. Sorry.
My impression is that overweight girls will maybe 'not mind' but tend to definitely prefer muscular guys who make them feel smaller.
Girls who are thin - some like muscles, some like lean.
I beg you to take up boxing. Your low weight is an advantage, you can get in shape and get toned, but more importantly, think and carry yourself differently. I thought I was thin till I boxed. Now I just think other people are fat and I'm a goddamn rapier.
I have a lean body with time throughout, and my lady interest seems to have a preference for it. So I'd say that bulky isn't the only way to go for male bodies. If you aren't scrawny then you should be fine.