Does Mace's aluminium intake manifold gasket suit a 99 VT V6 series 1 commodore?

If you're referring to the aluminium inlet manifold gaskets, as shown in the link below, then the answer is yes

http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectID=1469584

The only thing that you may need to do when you receive them, is slightly trim the valley gaskets that come in the kit to suit. This is easily done using a utility knife (also known as a Stanley knife, boxcutter, etc).