What would you recommend me with a Stage 3 cam kit to get the most out of my Ecotec engine? I'm also thinking of running 18 or 19 psi on a super charger, what would be its outcome?

These parts which are mentioned below can give you better performance.

Comp Cams http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/CAM604/SubProducts/CAM604

130lb Crow Cams Valve Springs. http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/SPG601/SubProducts/SPG601

Manley Performance Valve Spring Retainers http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/SPG604

Premium Viton Valve Stem Seals http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/SPG605

Rollmaster double row timing chain set http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/RLM601