I got it off qvc
http://www.qvc.com/qic/qvcapp.aspx/view.2/app.detail/params.item.K5963.desc.Cooks-Essentials-5qt-Digital-Pressure-Cooker-w-AccessoriesI think they also have larger ones. We have a small family so this 5 quart works well for us. I have to hack up larger roasts though which is a pain. If they have a 6 quart one it might be a smarter choice.
This is a great little machine. I use it almost every day.
Yes you can do either of the soupy things I mentioned above in a slow cooker or even on low on top of the stove.