This is actually a discussion for the hardware forum ... and I'd be suprised if a 'mod' doesn't shift it over there soon.
Go to the hardware forum, check out the tweaker's page ... especially not the parts about laying out your discs and usage ... that's a place so many people don't get right. Like above, people tend to focus on chip, ram, v-card ... but there's a HUGE amount of reading & writing to disc going on especially during playback as more effects are added.
The new Haswell E CPU is out now. THAT is what you want for a new editing machine. ESPECIALLY for heading into the future, which will involve 4K and other, maybe more DEMANDING codecs. SEE Eric Bowen's posting here on this forum regarding the test results for video editing using the Haswell E...vs. the older CPUs.
The Haswell E now has a new chipset,( X99), that brings MANY new features, AND, the Haswell E NOW features "quad channel" memory...to handle large amounts of data FASTER. The new motherboards have TEN SATA III ports, for a variety of HIGH SPEED storage options !! The OLDER motherboards are LIMITED to TWO SATA III ports.....PREVENTING creating FAST onboard RAID setups. The Haswell E is available with EIGHT,or, SIX cores...you choose !! Use at least 32 GB of system memory. Soon, Eric will post the results of the new Nvidia 970 and 980 video cards. in his video editing test. The 980 is ALREADY the top card in GAMING...BEATING the 780ti, DESPITE having LESS data throughput. The 980 MAY be the card you want....it is MUCH cheaper than the 780ti......down in the $500 plus range.
Use the new Samsung 850 Pro SSDs in your new system...or, the cheaper Crucial M550 series SSDs. The SSDs are now WAY more reliable than HDDs and are WAY FASTER, in many ways.