Is it sinful to have a thing for a specific kind of girl? Like if you only go for a girl who has facial characteristics that you look for. For example, there are some guys who like girls with blue eyes, short girls, or blonds. I have my own thing too, and usually I will only go for the girls who have that aspect. That is not the only thing I look at. I see if they are a nice person and if she has a good personality too. I also make sure before trying to start something serious that she would be a good wife or a good woman to have kids with. I would not go out with a crazy teen who is doing drugs, drinks a lot, or does sinful things. I usually try to look for a person who is a Christian or who is into the things of God. So even if a girl had those facial qualities, but was not a good woman, then I won't even go for it.
Just because a girl has that specific body part, it does not mean that I am only going to look at that. I asked this question to another person and that person told me to not focus on only one thing but to look at her as a whole.
Looking for certain physical qualities in a girl fairly typical in most boys. In a similar way, many girls look for certain mannerisms and emotional qualities in the boys. But then boys tend to be more visually oriented and girls more emotionally oriented.
It might surprise you, but I can give high odds that the characteristics you find most appealing are ones shared by your mother. That probably just gave you the willies -- it does most boys when they realize it. There are things which you associate with home life and comfort and so you naturally gravitate to things which trigger those memories.
The problem, which you realize, is that those characteristics aren't ones which actually define a good Christian or a good wife. While the presence of those characteristics will give you enough comfort to be bold enough to initiate a conversation and find out more about the girl, they aren't guaranteed to find you what you really need.
Actually, it can be a detriment if you are not careful. Whether you realize it or not, you are limiting your prospects based on characteristics that are not highly important. You may end up missing someone who is a really good match for you simply because she had the wrong color hair, shape of the nose, or bust size.
Instead of using physical characteristics as your first criteria, figure out the things which are really important to you in a wife. If you find a girl who has those qualities, and happens to have some of the physical characteristics you particularly like, then consider that a bonus. I remember laughing when the woman I asked to be my wife turned out to be from the same region of the country my mother came from, even though we met a long ways away from that area. I was looking for a strong Christian woman who loved children and was a good homemaker. I got as a bonus a woman who has an accent similar to my mother and cooks like my mother.
So, your friend is right. Look at women as a whole. But also have a mental list of what is critical to you for your future home life. Look for those characteristics first, and if other things happen to come along with the package that you also like, consider yourself extra lucky.