Nforce 750i Vs 780i for overlclocking?

I've got a Q9650 in the mail that should be arriving very soon (Thanks earthdog). Now I know my Asus P5n-D mobo (nForce 750i) will limit my O/C on this quad, so I'm wondering how the nForce 780i fares against the 750i for overclocking? Would it be worth upgrading or not? An Intel P45 would be nice but I require sli support as I'm planning to get another GTX 2600 in 2-3 months time. Thanks

EDIT: If I do get a 780i board it would most likely be the Asus Striker II formula

780i=750, but NV added the media 200 chip to add pcie 2.0. meaning in sli the first two x16 slot are pcie 2.0. then for 3 way sli, the 3rd x16 slot pcie 1.0/1.1 from the NB.