I am a newbie to PCing. We want to purchase a good used PC perhaps from a thrift store. I know I want stainless steel. Beyond that, do you have suggestions of the best performing brands? What should I look for to make sure the PC is in good working order? Is it just a bad idea altogether to buy a used PC? We are a family of four. What sizes are best? Also, I am just learning to can. Do you use PC for canning??