Best source for replacement parts

[My Alter Ego]

Looking to find the best source(s) for replacement parts for my 68 GMC 3500 Dually Flatbed. I am accumulating as many parts as possible to begin this frame up resto project. I have nearly all of the suspension components already, but am interested in finding a reliable source that offers good quality replacement parts for the interior upholstery, weatherstrip, glass and trim. I know there are several vendors out there, but am having difficulty, particularly with the interior upholstery. The colors aren't consistent between the different pieces I am looking to purchase. There seems to be a difference in the shade of the colors between the door panels, armrests, dash pad, headliner, seat cover, etc. Would prefer to find a source who can also provide samples in advance of my purchase. Am trying to avoid the huge expense of going to an upholstery shop to have each piece made or covered. Thanks in advance for any and all help.