I don’t have any decent pictures, but I installed the black velour and Naugahyde upholstery kit from Seatz Manufacturing on my original bench back around 1996. These are the best pictures I have:
http://www.seatzmfg.com/seatz/index.htm
The version I picked looked like this rather fuzzy photo they have posted on their website. It included separate buttons that were installed after the upholstery was mounted on the frame:
It fit perfectly and remains in immaculate condition, currently living in my son’s daily driver. The next time he comes over I’ll take a decent photo to show how nice it has held up all these years.
I don’t have experience with other brands, but the Seatz upholstery kit was first class and made accurately with quality products. I would highly recommend Seatz upholstery if they make something you like.