Can I connect a development or test store?

Yes, and it is a sensible way to see the product before pointing it at a live business. A development store with sample orders will produce a real statement, and the numbers will be as honest as the data behind them, which on a test store usually means small and strange.

One caveat worth knowing: a test store rarely has realistic costs, so the margins will not tell you much about your own business. If you want a feel for a full statement on a real catalogue, the demo account is a better look than a development store with twelve orders in it.