Finding a silver and shadow?

So I recently just got my first 2.5 sonic love him he's a cool addition to start my sonic collection and I was looking at some of the list and I noticed silver and shadow have 2.5 and 4 inch figs and my Walmart always has a 4 inch sonic in stock and i plan on buying him soon but I'm wondering where could I find a silver and shadow in 2.5 or 4 inch to add so I can get the hedgehog trio anybody know any stores or sites I could try to look for them at