I don't think that IFX-10 will work with X58 / i7 motherboards, as every single one of them seem to have a backplate already. I can't really imagine how you'd get it to work effectively.
There are some motherboards out there with LGA775 mounting holes, such as the Foxconn Bloodrage. You could give it a try with one of those.
I'm still of the opinion that the way the new motherboards are being made, the IFX-10 won't work, and might even mess up your board. See the attached image to see what I'm talking about.
I think you'd be better off getting a good cooler for the other side: TRUE, water cooled, or what have you.
Image of an Asus board w/ the backplate I'm talking about: