If it were me, I'd get some leggings and matching gloves from welovecolors for Rogue, since they'll be from the same fabric dye batch. (The leggings from my Loki costume are from there, and coincidentally are the same shade~)
As for the top, I'd aim for a polyester satin (Like the casa satin at Joanns) with interfacing for stability and lined with cotton and boned for a muted shine, as super shiny tends to photograph oddly and looks kinda tacky, at least in my opinion. Applique the white symbols with a pleather so that it'll be a bit shinier and you won't have to worry about fraying, and then a poly-blend for the belt, trim, scarf and pouches. Heavy craft interfacing will be your friend here.
I'm not too sure on the wig color/tone. I know that the brighter colors tend to look better on people with darker skin tones from what I've seen, but I might ask around the wig forums, just in case. I personally think the Luthien in pumpkin would be gorgeous, but that's just my opinion. Here's the color:
Luthien pumpkin: http://www.flickr.com/photos/ardawig...57627559061558