For quarter panel scoops, check out Sage Glassworks
"sgw AT gmail dot com" (written that way to try to confuse the bots)
He used to make all the pieces for Fiero Warehouse (who bought out IRM.)
Here's one type that he offers. Essentially all you need to do is prime and paint.
When I installed mine, I had to elongate one hole, at the bottom. Otherwise they fit perfectly.

Edit - If you're adding the GT bodywork to your car, you can order these panels pre-drilled to accommodate the ground effects.
(Mine doesn't have the ground effects. All the panels are stock Formula except for the side scoops and the fastback stuff.
Strangely enough, your car was part of the inspiration for mine, years ago.)