If you went with either the EK Supreme, Dtek Fuzion, DangerDen MC-TDX or the Apogee GTX you couldn't go wrong. Those are some of the top performing CPU Waterblocks on the market.
Dtek offers a nozzle kit as an extra for the Dtek Fuzion that splits the waterstream so that it hits both dies on the quad-core with much higher pressure than is standard.