seeking advice - turning an heirloom pin into a ring

I have this beautiful family heirloom pin made of diamonds and sapphires and I am interested in having it remade into an engagement ring (as was suggested by the family member who gave it to me). I am a jewelry novice and don’t even know where to start - I don’t know what is possible in terms of design (I love the look of it and would want to preserve some of the original character) and I don’t know where to go for a consultation. I am based in NYC - does anyone have suggestions for where to start with finding a jeweler and consulting on design? Also, does anyone know what to expect in terms of cost?