Here's a long thread on the topic - http://www.tomshardw...246-28-2500k-2600
Most there say get the i5 and use the rest for a better graphics card if it makes sense. If it takes $200 more to get 10% better frame rates, then it might not be worth spending more on the card. But, if the point is to get the kicking-est machine for $1000, then, well, maybe leaving out everything except the fastest essentials makes sense ($500 graphics card, 1-2 GB RAM, fast CPU, no optical drive, no wireless, no sound card, etc.), and add the rest later. I dunno.
The CPU is one of those rarely swapped things (that happens after hard drives, more RAM, etc.). IME, by the time you're thinking about a new CPU, motherboards have moved on so you end up replacing a lot more than the chip. So my general philosophy has always been to get the best CPU for my price-point (which used to be $200, but I haven't bought a new PC in a while). And I'm not a gamer. :-)
Presumably if frame rates and latency and all the rest matter most, you can turn down the graphics effects and so forth to prolong the system life for another few months.
Bottom line: You're probably set as you outlined the system above.
HTH.
Cheers,
Scott.