Do you know something we don't about a 2700K?
I think you mean 2600K.
The 2600K is an outstanding chip, but if you have a budget, and the extra $100 is important to you, look at the 2500K, and spend the $100 on upgrading to a GTX580, or a SSD for boot and apps. Very few games use more than 2 cores, certainly 4 is enough. The extra multiplier on an unlocked cpu is not much worth it.
I have seen no benchmarks about the value of the extra L3 cache in the 2600K.
I think I would not pay much extra for a P67 motherboard. Most of them will do sli nicely, and OC well. Most have usb3.0, and 6gb sata.
No need to pay for competitive overclocking capabilities. Actually, the sandy bridge processors really don't need to be overclocked at all.
8gb is the new 4gb. Unless you have an app that can use lots of ram,like photoshop stick with 8gb.
Do not pay much extra for higher speeds than 1600, lower latencies, of fancy heat spreaders.
Note that if you ever wanted >16gb, you will need windows-7 business or higher.
A SSD is very much worth it. Everything you do will feel so much snappier.
Gen3 drives are supposed to launch soon. I expect slightly better performance and a lower cost per gb.
Do not be seduced by glowing synthetic sequential benchmarks. 90% of what you do will be small random reads, and a few small writes.
Look for a drive with 50k iops for small randon reads and writes.
There are the final specs. I am over budget about $400 bucks but I'll hold out an extra week to save for it. As it is I have to give the cash to a friend and use his card so the roomate does'nt see how much I just spent LOL.
That doesn't include the new 42" Monitor or the Hotas WartHog that are on the ASAP list either. More expensive than a drug addiction