Searching for Niece and Nephew

I am in search of my niece and nephew... Niece's name at birth was Jordan Savanna Lee Evans, DOB: 7/26/1997, age 5 at time of adoption... Nephew's name at birth was Zachary Frederick Austin Evans, DOB: 1/2/1999, age 3 at time of adoption... they were both born in Cape Girardeau, MO, my brother and sister in law were living in Arkansas when they were placed for adoption... the info I have on adoptive parents is that they lived in Manhattan, John (adoptive father) was an Architect and Johanna (adoptive mother) was a Freelance Photographer... they did have Jordan and Zachary enrolled in private school... any leads would be helpful... feel free to email me at ritoru.mijikai@gmail.com