We all want thing but we must ask our selves is it worth the time and money, trust me you will need a lot of money and maybe a day for labor.
here is an article on installing the spoiler:
zerothread?id=273340
If it were me I would buy the trunk with the spoiler attached and make sure the trunk is in in good shape and same color, that way you save money and you can always go back to the original trunk with out a spoiler if needed.
But besides the spoiler you need the Torsion bars: $28 right, $29 left, Torsion bar clip: $2.54, upper spacer for spoiler: $8.88 and you need the sun deck with out a the 3rd brake light and it need to match the interior color as well but this is probably better found at a junk yard.
I think it can be be done though.