xigmatek gaia (dual fan) or hyper 212+

Hey guys, I am looking for a couple of different things. First and formost, a good CPU cooler for the 2500k. I was looking at the hyper 212+ and the xigmatek gaia (and adding a second fan to the Gaia). What do y'all think is the best option for a 4.5ghz 24/7 overclock, and how high do you think I can push the 2500k in the best situations with these coolers.

One more question, how much will overclocking my ram and CPU benefit hd video editing and effects rendering in premiere and after effects.


Case-Antec 900
CPU- i5 2500k
Memory- 16GB DDR3 1600 ripjaw series
GPU- ati radeon 5870
PSU- 900w antec psu
Mobo- gigabyte z68
128GB c300 solid state and 32TB for data storage.

I've heard the Mugen 3 can be found at a good price.
The Hyper 212 was the best performance per dollar deal at $30 or so. The Gaia at $28 is equivalent.
4.5 24/7 I would suggest the Mugen 3 as the cost leader, Noctua nh 14, Scythe Ninja 3, Xigmatek Dark Knight, etc.