Making a spoiler

I have a 96 Impala SS with a small bolt-on spoiler. I hate it. It looks like a bolt-on spoiler. I want to make a flush steel spoiler and weld it on and I need your thoughts. Here is what the trunk looks like (sorta) when the spoiler is off:
http://i162.photobucket.com/albums/t264/curtis73/trunk.jpg

Here is sorta what the spoiler looks like when bolted on:

http://i162.photobucket.com/albums/t264/curtis73/trunk1.jpg

Here is what I want it to look like:

http://i162.photobucket.com/albums/t264/curtis73/trunk2.jpg

I have to admit my fabrication skills are great with lots of heavy mild steel; structural, frame work, suspension, etc... but body work eludes me.

I thought maybe I could use the original spoiler as kind of a mold/buck to shape some sheet steel around, but should I try to do it as one piece or as two together? Should I scrap that whole idea and try to build it from fiberglass and epoxy it on? Should I try to do some kind of composite construction like this? :
http://i162.photobucket.com/albums/t264/curtis73/trunk3.jpg

Maybe even three pieces of steel; one flat piece for the top, one flanged piece for the bottom, and a long piece of 1/2" steel tubing for the radius? It would all get welded onto the trunk, then probably backfilled with expanding foam for rigidity, and of course the ends of the spoiler would be capped off with steel triangles and the whole thing lightly filletted with lead or filler as necessary.

Thoughts? Am I crazy? Any input appreciated. I want a seamless look, as if the spoiler were stamped right in the trunk sheet metal. here is a photo of the spoiler that is similar to the stock one on the trunk:

http://www.streettrendsinc.com/Merchant2/graphics/00000001/11242.jpg

use 2 pieces of sheet metal, both curved running the length of the bootlid...the lower sheet curved upward and the upper piece curved down. weld the pieces on and use filler to perfect the shape. prime, prep and spray...voila!