Are you thinking about adding a functional hood scoop, or attaching a cosmetic one? The cosmetic type could be purchased on Amazon, eBay, or any automotive store. I don't care for these, but that would be the cheapest option, if you only want the look.
For a true scoop, you'd have to attach it and cut a hole in your current hood. Your other option would be to get a hood from a Trail, Off-Road, or Pro. I don't know how many cars get totaled without taking hood damage, but it's worth posting a WTB ad.