I'd like to go up to an i7, when I built this PC the i7 was still pretty new and there was no unlocked version yet. I was able to clock an i5 unlocked higher then the i7 at a peak clock. As for the shader I am using it's this - http://www.minecraftforum.net/topic/940974-175sonic-ethers-unbelievable-shaders-v101/ Posted just above. Dang nice! I might have to build a new PC again soon. I've always wanted to do water cooling and SSDs in Raid0 as well, so might do it finally in my next build.
i7's don't perform better game-wise.. I'm running a broken GTS 450, still waiting for the 800 series tho... rumours say 2015 plis nvidia
These aren't my builds, neither am I using shaders (Using chunky) but I don't care (Well, the last one is but I'm not that proud of it).
Alex once took some wonderful shots of my Village on smp2, I'd like to see what your capable of coming up with