I've been working with x-cart much lately, and I was thinking about using it for a much larger site, but I don't know if it can handle what I'm looking for. I need a platform or strategy that can allow for as many users as possible where each can post multiple products (hopeful up to a hundred, but that's less important), but in their own private catalogs. So what am I looking for? With x-cart, I'm used to customizing it with jquery, smarty, and php, so I can handle that much. Can I extend an existing shopping cart, or is there one that fits my needs?