Hot OC'ed cpu, need better cooler.

Hello all,

My CPU is an i7 930 OC'ed 3.8ghz with voltage at 1.375v. (It's on auto so sometimes reaches 1.379v.)
Motherboard: gigabyte ga-x58a-ud5
case: corsair obsidian 800D

Few days ago I bought some extra fans to help airflow in the case and i am also about to buy a panel to control the voltage of some fans to increase it.

My Cpu cooler is Coolermaster N520 and my cpu goes 85-89 (depending on core) degrees while using wPrime test. I feel this is abit too much especially when room temp is 20-25 degrees.

I am between Noctua dh14 and Scythe Mugen 2 rev B (with replaced 3k rpm fans scythe ultra kaze). The total price is around the same for those two on amazon.co.uk (since i would buy the extra fans for the Scythe cooler).

Any advice on which to pick? Also note my ram is Dominator GT so the heatspreader they have on top is tall as you know. I also have a kit of corsair XMS3 rams 1600mhz 9cas to replace just in case I buy smthing that doesnt fit but the Dominator GT 2000mhz 8cas is... much better in terms of quality and I would rather not change it.