I feel you man. I recently went through trying to get parts installed on my Z and the guy that did the work not only fitted the aftermarket parts incorrectly. He managed to damage other parts of the car as well. If you are near Huntsville, AL do not let Matt Hornbuckle do any work on your Z. I think since my incident he has switched to doing detail services as body work is not in his skillset. Personally I wouldn't let him touch my Z or anything else I own ever again.
As far as finding actual Sunline Racing parts. Try these guys.
370ZTUNE.com