Which iMac to get for FCP editing? What upgrades?

I know the iMac is not ideal for hard core editing.
but as that is the price range I am in I want to make the best choice possible

I will be using it for both video editing (FCP 7 and possibly some FCP X) and graphics stuff (PS, ect..)

so my questions are...

1. is there a big difference between the i5 and the i7 chip when it comes to editing (enough to justify cost)
2. the Radeon HD 6970M video card comes in both 1GB + 2GB options, Logic would suggest the 2GB of ram would be a good choice but will it make much difference in editing or will it mostly make a difference in gaming and 3D rendering (which I won't do any of)
3. Also is it possible to easily update a video card in a new gen iMac?

any other suggestions comments are for sure welcome.
thanks!

Definitely upgrade to the i7 and don't worry about the extra 1Gb of memory on the video card.

Memory on video cards (at least for video editing as far as my experience goes) isn't used that much.

You definitely want a more powerful processor because the CPU handles quite a bit of the rendering.

You can do a Google search to see other responses and benchmarks on different amounts of video ram. Overall, you won't see any significant improvement.

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