What would Mace recommend with the 3 stage cam kit to get the most out of my Ecotec engine also thinking of running 18 or 19 psi on a super charger?

You may consider the following parts which will give you a 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