Update November 2015
Noctua NH-D15 CPU Cooler - I decided to replace the the Corsair H60 SE Cpu cooler that I have used since January 2013 to cool my i5 4670k. I decided I wanted to overclocked it to 4.5ghz and I felt that the H60 wasn't sufficient for this task. The options that I considered were the Corsiar H80i and the Noctua NH-D15. I decided to go back to air cooling because I did not want any chance of a leak in my system and because with air cooling there's less chance of anything failing. Watercooling is great but I don't think it's better than air cooling unless it's a custom loop.
I am very happy with the Noctua NH-D15. It's quiet and the performance is awesome! I overclocked my CPU to 4.5ghz with a voltage of 1.295 and I have tested it with realbench running for 1 hour with a maximum temperature of 74 degrees. It was easy to install and the quality of the cooler is second to none.
Update October 2015
Acer XB280HK 4K Gsync Monitor - Ever since I updated my graphics cards to the 980Tis I wanted a 4K screen to be able to truly take advantage of the extra horsepower. I saw the Acer as my only real option as it was the only monitor to combine 4K with Gsync so when it came on special with a $100AU off I had to grab it. I know some people will say that the I should've gone the 144hz 1440p Asus/Acer screens however they are priced at $1049AU whereas this screen set me back $699AU so that made the decision a lot easier. I have to say 4K gaming is so sweet! Everything looks so clear and you notice different details that you would not normally pick up when playing at this resolution. I get constant 50 - 60 FPS and when it does dip I cannot notice due to Gsync.
The other change I made is I picked up a second hand EVGA ACX 2.0 cooler for Titan X for $60AU that also fits a reference 980Ti. These are not normally sold where I live and I can only get them from Amazon for $120AU. With the cooler installed I have stopped the top card from throttling with the temperature hovering at 70C degrees whilst the bottom card stays at 76C degrees. I know that aesthetically I have gone a step back by having different coolers on the cards but the lower temperature was worth it!
Update June 2015
I've recently updated my earlier build with some some new additions.
I got a really good price for my r9 295x2 so I decided to sell it and upgrade to the 980ti in SLI. I decided on the reference coolers as I would like to put them under water when I can save some more money up but for now they are performing great!
One of these cards is amazing let alone two! I am waiting for some good 4K G-sync monitors to come out however I currently upscale to 4K and these things do not skip a beat! All the eye candy turned up at 60 FPS. I've had to create a custom fan profile and with it the top card reaches 83 degrees however it does not throttle whilst the bottom card stays at 75 degrees. I also have two fans blowing cool air over the cards. The top card's fan ramps up to 65% to maintain the clock speeds so it is not a massive jump from the 56% it goes up to when the fan profile is set to default. That being said I cant wait to water cool them so they can be overclocked!
I've also upgrade the RAM to the Kingston Hyper Fury X 16gb. I really like the low profile of these sticks as they don't get in the way of other things.
If anyone is looking for a comfortable chair I cannot recommend the DX Racer F Series enough. It's perfect for people under 100kgs and sitting in it for prolonged periods is very comfortable. I've got a bad back so the lumbar support does help.
Other than these new additions the rest of the rig remains the same with the i5 4670k and the Maximus Hero VI.
My next purchase will be the water-cooling parts and a 4K G-sync monitor. If anyone can recommend some good water cooling guides please leave the in the comments.