If you live in the SD area and want a good consultation try Dr.Frank Coufal (he's a Neurosurgeon). At the time I saw him for a 2nd surgical opinion (WC) re 2 level ADR he didn't perform lumbar ADRs, rather fusions altho he went along with 2 level ADR recommendation.
I'd also recommend talking to Mark here (mmglobal)
GPN Artificial Disc Replacement ADR
He accompanied me to see Dr.Delamarter, Dr.Regan, and Dr.Coufal. Definately worth talking to Mark.