Go for Superleggeras mate, they are way ligheter.
But my choise would be Buddy Club P1 QF 17x8 inch = 6.15kg/each!!
Or maybe the Volk CN28 those are light as well...
If you have the money there are only one option.. Volk TE37 Magnesium 18x8.5 i think is the smalles dimension... 6.0kg!!
But they are like $1300 in msrp