Would you be okay picking out your own engagement ring?

A little background. Together just over 5 years. Own a home together, we have a almost 2 year old little girl. I love our little family and he is such a good man and daddy. I have been married once and through a nasty divorce. He gave me his dead mothers ring. She was a large women and I'm extremely petite. (I'm a size 4 ring finger) Her ring was huge and even thejeweler recommended we set the center some in a different ring because they were going to have a really difficult time sizing it down. My X was not having it. I spent our whole marriage feeling like I was wearing someone else's ring. (Well.... because I was) So fast forward. My now so knows about the ring and says he wants me to feel like my engagement ring is mine. My style, for my thin fingers, exactly what I want. So he wants me to pick out my own ring. He will still go buy it and plan how to pop the question and surprise me. Just can't decide how I feel about it. I love the idea of getting what I want, but feel kinda wired about being so involved. What would u do?