Quickbooks Premier has many different versions within it, and you'll select which one you want when you install it. They're all basically the same, except it labels things differently and has a few different options depending upon which one you select.
For example, the Retail Edition has Customers and keeps track of inventory, while the Professional Services Edition calls them Clients and is more focused on services. They also have different report templates focused on the kind of information you'd need. But they're all the same program and you can decide later on to change it if you preferred a different version. For myself, I use the General Business Edition, as it gives me more flexibility for what I do, but I could see why some people would prefer a specific version.
According to Intuit's website, the non-profit version can create Form 990 to submit for tax purposes, though I've never done anything with non-profits and can't tell you how well it works. But again, if you buy the main Premier software it includes the non-profit edition. And that's a key advantage over QB Pro, as Pro doesn't have any of this customization. Hope that helps.
Gene S
ChooseJim