Pictures? What does the hardtop look like? Where do you plan on routing these ducts?
Shooting in the dark here, but generally the rear is where you can make the most difference. Miata are similar, take a look at these fastback fiberglass tops:
https://www.google.com/search?q=miata+hardtop+fastback
For the lower rear, a diffuser. Here's an example on a Lotus:
[IMG]
[/IMG]
For the airflow in the cowl area:
Air vents as at B would fit well with the generous panel gap at the front of your doors.