I have their letterboxed LD of this movie as well as Sony's 15th Anniversary DVD...the HD upgrade is overdue, as this was one of the seminal films of the early '80s and for me, Lawrence Kasdan's best overall work as both a director and writer...
Sony has released "The China Syndrome" in Germany on a region-free pressing for $10 Euros...which converts to US$15...it's authorized Sony/Columbia product, so you can be assured of quality control and decent picture/sound...