Painting seats vinyl or fabric IMO is just a temporary fix since a seat is a high wear area and by painting fabric you loose the whole soft and plush aspect of it which why you would want it in the first place, that and not wanting to burn your butt on a hot summer day.
For me when doing an interior color change I always start with buckets that are the color and material I want and match the rest of the interior to those.
Getting a Gbody rear seat reupholstered is far cheaper and easier than having a pair of bucket seats redone to match something and it is easy to install the upholstery yourself.