Check out the free youtube videos by Sailrite.com There you can find plenty of demonstrations about whether or not that sewing machine would work. I have not personally attempted any kind of upholstery sewing yet, but I have the same idea as you and that's doing it yourself. From what I have learned thus far, you should probably avoid that machine. Not because it isn't a good deal, but because there are plenty of newer machines with all sorts of attachments that make sewing heavy fabric easier. One thing that I know for sure that I will be looking for is something called a "walking foot." That machine may never have been engineered with a walking foot in mind. The idea is that a walking foot(of a larger industrial type machine) helps to move two pieces of heavy fabric along and keeping the stitch consistent along it's length.
From studying the craigslist pictures, I stand by my recommendation NOT to buy it. It's really made for garment making, not vinyl or heavy fabric work. For me, I'll be looking for a second-hand industrial grade Juki machine. My inspiration to buy a Juki is because of some talented guys on Youtube doing professional auto upholstery and restoration. Their channel is
www.youtube.com/user/younggunsfab/videos