You are good.
I have become a bit jaded on the subject of haswell cooling for overclocking.
How high you can OC is firstly determined by your luck in the bin lottery.
I had high expectations from the Devil's canyon parts and their better thermals.
I found out that the thermals really do not matter unless, perhaps, you are a competitive overclocker.
Haswell runs quite cool, that is, until you raise the voltage past 1.25v or so.
Once you go past 1.3v, then you really do need very good cooling to keep stress loads under say 85c.
But, the consensus is that voltages higher than 1.30 are not a good thing for 24/7 usage.
I have been unable to find any official Intel recommendation on what is a safe vcore limit.
To oc, just gradually increase the multiplier in the bios, leaving all else on auto.
Stress test with OCCT which will stop the test if temperatures reach 85c.
Monitor vcore with cpu-Z.
Even if you can handle the heat, how much do you really need that extra multiplier from say 4.4 to 4.6?
Your psu is excellent.
Here is a chart that shows what graphics cards you can run on 550w.
I suspect you have a R9 card in mind, and be advised that they are more power hungry than nvidia.
http://www.realhardtechx.com/index_archivos/Page362.htm
A 550w psu should run a card as good as a GTX980 or a R9-380X.
Now, With Skylake now available, there is absolutely no question in my mind that a new build should be Skylake.
a. Prices for cpu, z170 motherboard and ddr4 ram are almost precisely the same.
b. Skylake has an estimated 5-10% performance improvement per clock over haswell.
c. 14nm runs cooler, you get a decent overclock without the need for exotic cooling.
d. The Z170 chipset permits the use of much faster ssd devices on the horizon. Samsung 950 pro for example:
http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/ssd950pro/overview.html
e. skylake can be upgraded in the future to kaby lake.
I suggest for a new build, you look at a i5-6600K, a Z170 motherboard and DDR4 ram.
The cost should not be significantly different.