Wizcrafts

The Juki 8700 is a bottom feed only machine. You will have to either order one with the most aggressive teeth, or buy an aftermarket feed dog with aggressive teeth if you're to have any hope of the moving the material. Really, auto upholstery, like any other type of upholstery, calls for a walking foot machine, with at least dual feed. The Sailrite portables all have top and bottom feed. The Consew 206 series machines all have triple/compound feed, which is the strongest and keeps all layers aligned as the needle move with the feed dog and the inside foot. You may be able to find a used Singer, Consew or Juki walking foot machine, complete with a table and motor, well within your stated budget.

It is always best to feed spooled thread off the top. Feeding sideways adds unpredictable friction that changes as the spool unwinds. If you need a thread stand, buy one. They come with raised bottom plates that screw onto a table. The stand threads into the plate and there are usually two cone brackets, and thread loops above them.