I can tell you from personal experience and reading all forums I can find on video editing, that the hugest weakest link....is storage speeds. SSD are horrible for video editing. Sure they offer great speed 'boosts' but consistency is not their strong suite. But that said, hhd steady speeds are horrible. The best thing ever you can do for video editing (quad core preffered, some kind of gpu that is compatable with your software, 16gb ram, bluray burner) is get an actual external raid cage, 4-8bays depending how much storage you will need, then get a minimum of 5 drives. I say 5, as you want at least 4 for raid 0, and one for mirroring (its actualy a raid 5 setup). Your not going to use up all this space no, but raid 0 gives you ssd speeds, at a cheaper price, with consistancy. Seagate hhd's are rated horrible for failure rate ( I hae 4x 3tb and wish I knew this before hand), best hhd you can get is wd black. If you cant get those, get wd red (nas). Get 2-4tb whichever is more cost/size relative.
I'm not kidding, the majority of what controls any performance in video editing is hhd speeds. Quick rundown of my setup running either sony vegas 12 or cyberlink powerdirector 2 ultimate.
Producing 3 videos equaling 10 min. Only swapping original audio for enhanced, and combing the 3 videos to one. From avi format to avi format.
From ssd to same ssd
drive 1 550mmb read, drive 2 550mb write, processor 64% 3.5 min total time
from ssd to hhd
drive 1 106mb read, drive 2 106mb write, processor 14% 12 min (total speed is limited by the slowest drive)
from hhd to ssd
drive 1 106mb read, drive 2 106mb write, processor 16% 9min (again total speed limited by slowest drive, but hhd did bump up slightly due to read instead of write)
from hhd to hhd
drive 1 106mb, drive 2 106 mb, processor 9% 21 min (totally limited by slowest drive, which are both this time)
Now when you use the same drive for both read and write, they split the transfer speed, but while doing this each one trys to take more so speeds fluctuate)
ssd to same ssd
drive 1 200-300 avg 250mb read, drive 1 200-300 avg 250mb write, cpu 33% time 8min
hhd to same hhd
drive 1 50mb read, drive 2 50mb write, cpu 4% time, 32-42 min
Hope this helps a bit. Now this isn't adding effects or anything, that will then start to use processor, and graphics cards. But that, is all added to cpu and gpu usage, but times are still dependent on data speeds. Unless you can get your data speeds to about 300-400mbps read and write, your processor will never get to 100% on an i7 or fx 8350.
GPU, depending on your software at which is uses, typically memory and cuda cores are used for programs that ive seen and run. Highest ive seen gpu usage go is about 30%, with gpu memory at 100%.
Now cpu wise, while adding effects and actually editing and enhancing the videos, the more cores the better, every program ive used allows for maximum cores to be used, whether it being dual, quad, quad with hyperthreading, six core, six core with hyperthreading. All this will make a huge difference (only if data speeds aren't maxing first). The i7 six core 4930k is my cpu or choice, but requires $500 chip, $300-500 for board. The i7 4770k is a quad core of that, and is great, $320 and board asus hero $200 gives best options features for the best price.
Ram, 8gb minimal, but remember each window you have open, program you have open, takes a chunk away. Video editing ill have 5-10 video edit files open at a time and run up to 80% max on 16 gb very often.
HHD, I already explained the raid cage, but you'll still want a minimum of 256gb ssd for boot and programs, grabbing a small 64-128gb ssd for a scratch disk if your using photoshop will also net huge speed increases , and a minimum of 1tb hhd for non movie data, or finished products.
Video card, do a quick search on the programs your using and see if they prefer amd or NVidia. The majority I use like cuda which is a NVidia thing. You'll see performance increases going up to a titan black or something very nice and expensive, but those are $1000. Just having a capable one will make 10x the difference than without. For that nividia route, yes 760 or 770 (the more ram the better, expl 770 has 2 and 4gb versions, big difference there), amd the 290x gives just excellent performance but at $600, but the 280x is also a great card with 3gb ram.
I say bluray burner, as if there just small videos it should fit on dvd, but if your talking a lot of home movies a 4gb dvd isn't going to cut it. bluray offers both 25 and 50gb on one disk.
Case, its all personal preference. I'd say pick out your parts first, then determine how big or small it needs to be, find something that looks good as youll be staring at it for a long time, and make sure it fits your parts and that it has good airflow.
Power supply, you don't need a $120 seasonic, but don't skimp at all on it. Big name brands and well rated, if your psu goes out, your whole computer goes with it. I'd search sales on xfx, seasonic, evga, and corsair professional I think hx series. But expect to find a sale and end up paying $70-120.
Windows 8-8.1. ITs quicker than 7, offers more security and features. Start button is coming back soon, otherwise programs like start8 make it just like windows 7.
Monitor, your going to be staring at that all the time. for video editing your going to want a nice display. Pick a size that your eyes are comfortable with, sometimes bigger makes you strain your eyes, sometimes smaller does. Sometimes the bright nice Samsung/asus picture hurts peoples eyes, sometimes the mattier type from asus/aoc/dell hurts peoples eyes.
One note on monitors, most video editing programs let you utilize a second screen for just the preview screen. I cant tell you how nice of a thing it has to look at a full screen preview, it helps you notice things you might miss and have to go back to, and it helps from having to creep up to the screen to look at the preview that the top right half of your monitor normally. Yes you can make it bigger, but then you cant edit at the same time.
For pricing, raid cage/bay with raid controller, should be around $200-300 depending on size, hhd's expect to pay $80-100 a piece. So that's $200+400 or $600. I know huge chunk of change but its going to eliminate the bottleneck of your system. I'd hate for you (like me) to spend $2000 on a system and to stare at cpu at 20% b/c your hhd is at 100%.
But you don't need a second gpu. Not right away, the hhd cage will make a substantional impact vs a second gpu.
But processor, i7 4770 $300
Asus delux z87 board $160, or hero $200 (will give more ports and nice features but both are good)
Ram, 2x8gb $100
SSD boot 256 Samsung evo $150
HHD $700 (includes raid bay, 5 hhd for bay, and 1 hhd for computer)
gtx 760 $250 (or 770 for about $330 which is an upgrade but keeping budget)
bluray burner $80
power supply $80
Case $80
windows $80
Be about $1900, id get the 770 then. Ill go to pc partpicker and make a build.