AFAIK, there are no RE inspired schools in OKC.
Believe me, I've checked into them all. However, there is one school that either opened this school year or will open next school year that is democratic. The way the director described it to me sounds exactly like what posters have described as a Sudbury/democratic school model. I know there will be a lot of dance, drama, free choice of materials, art, child led curriculum, etc, which is a part of the RE idea of education. I believe it's called Keystone School and it's located in Edmond, which is just NW of OKC and a very drivable distance. It's in a large house with beautiful land for hiking and a horse stable and a barn with animals. The tuition is $8,000 a year, which is higher than all but a few schools in the area, but it sounds really good. Right now, they are only planning to be PK-8th grade, but I hope they change their mind and decide to go thru high school.