As the other guys said, GTX 980 graphics card. I'd say the choice between MSI or Gigabyte is just personal preference. I opted for the MSI but it was out of stock so I settled for the Gigabyte. Use a website where you can compare the different parts. I forgot the one I used but it was easy to use and really cool, will look it up for you.
You'd want the i7-4790 4.00 ghz CPU and then pick any motherboard, that's what I did lol. I ended up buying the Gigabyte Z97X-Gaming 5 chipset, but I really wanted to get the MSI Intel Z97 Gaming 7 chipset but it was out of stock and I couldn't wait for it. I'm satisfied with the Gigabyte though and it's SLI compatible as well as M2 memory which is pretty much the future.
If you really want to spoil yourself get a Samsung 128 or 256gb M2. It's more compact than the SSD's and they have really great reviews. Do some research into it - the Samsung 256 and 512 gb is by far the best at the moment and the 128gb isn't that expensive. Use that for your OS and important programmes, it will run really fast. Then get a few 2 TB hard drives for how many space you need. Just make sure whichever motherboard you choose supports the M2 memory, and the capacity. Many of the older motherboards will have a problem supporting 512gb.
The Chasis is again personal preference. I can tell you that I got the Corsair Carbide 200R ATX case and it's awesome. It's not big (my brother has this huge case that takes up A LOT of space and he doesn't even use all the slots). The 200R is small and compact but it can still fit in 4 SSD's, 4 HDD's and it has more than enough room for the big GTX 980. It's cheap and it's effective, honestly. Another good chasis is the Fractal Design R5 but it's a big case.
Regarding RAM get DDR-4 but make sure the motherboard supports it - otherwise get Vengeance DDR3.