@Peter: I too am a 250 GTO fan. I decided to build mine from scratch. I have a build thread here:
C5 gto - All MetalShaping
Mine is LS powered as well but also has supercharger and converted to SOHC. I considered a 240Z base but decided to custom build a space frame. This decision has added years to the build but it's all about the journey and less about the destination
Thumbs up to your build!!!