you can get them used and paint to match, might be best due to if you get already painted the paint might be more faded or not enough what not and not look exactly right, and even with taht being said when the cars roll off the assembly line the scoops are not the exact shade they are off, especially noticable on black and red, same with spoiler and hood scoop if you have one, you can really tell under UV light.
i would go to ebay, check speedconcepts.com or .net cant remember which he has alot of take off parts and they are pretty darn cheap, also check stangparts.com. I wouldnt pay much for em so keep a look out for a cheap pair, install however lol i would just leave that up to the body shop.