Need advice with japanese hair style products

Hi Minna!
Need some advice with japanese hair products. First let me tell you about my hair situation. My hair is kinda straight and tends to stay flat when it's long. Currently my hair is long and it keeps staying down after wash. I'm trying to get a wavy flow style in my hair. That's why I've been using a hair band in front. But when I remove it, it tends to be flat again. So you can understand, my hair is kinda stubborn. I want to get rid of this flat stubborn hair.

Here I would like to mention that, I have been using Tsubaki premium moist shampoo and conditioner. I found that it has sulfate in it. So it might be the reason, my hair keeps getting down. That's why I decided to change my shampoo. But there are so many options out there in Matsumoto kyoshi and donqiue. It's really hard for me to choose the right shampoo and conditioner for me. That's why I would like to ask you guys if you can help me regarding this matter. Also I will very much appreciate if you can give me advice on how to get a wavy flow hair without my hair being flat.

Thanks in advance.