I'll probably be working on a custom hood for my '87 as well when it gets warmer. I've done some research into the "air deflector" stuff and the issue with it is that unless you have wind tunnel testing and such, you can end up with something that doesn't work just as easy as something that might.
I also hate the typical cowl hoods out there as well as most any non-stock hood on an Olds. They just don't flow well with the body lines of the car and tend to look like an afterthought. However I think if you design one similar to the F-body in your post, it would look a lot better than the typical G-body cowl hoods.
On most any aftermarkt cowl scoop, their sides are always straight up and down for the most part. I think if you do a wide angle on the sides (45* or so) it would help the transition from a flat hood to the cowl portion much more pleasing on the eye.
My idea is to make a cowl scoop that actually starts at the very front of the header panel and is the full width of the hood between the two body lines that run towards the windshield.
I'm thinking if I take a few sheets of 1/4" plywood or masonite and cut templates out of it for the profile of the hood and scoop, then glue styrofoam in between the sheets and carve it to the shape I want, I can use that as a mold to make the fiberglass.