I do not know about new seats- but recommend Latemodel Restoration Supply - Mustang & Chevy Truck Parts
for replacement upohlstery. You can choose cloth, vinyl, or leather. I have a 91 vert which burned my *** with the vinyl. I just replaced the seat covers with a cloth version so I can leave the top down- jump in and go.
The kit came with a tool, hog rings, and padded upholstery. All I had to do was remove all the hog rings on the old upholstery and note locations of hog rings on the solid metal rods in the seat. The solid foam structure under the vinyl/foam coverings was in great condition.
It took me about 6 hours to do the complete car (about 2 hours per seat).
Warning- Do not just start cutting the upholstery off. I got carried away on the back side of the seats and did not realize the foam is clamped down with cloth snaps. Let's just say I had to do some sewing to the foam/cloth ends to correct my error.
I know this is not what you are looking for- but hope it helps!