7850 Overclock

I recently purchased a 7850 since I have heard a lot about the card being such a great overclocker. I was just wondering if my current overclock is good and if I should upgrade my cooler on my gpu to an aftermarket cooler because I was wanting to overclock a bit more because I believe I have a little bit more headroom but I want to hear from you guys. As of now I'm only reaching 55c in Unigine with the settings at 1920x1080 x4 AA 16x AF Tessalation: Normal and Shaders: Medium I achieved a score of 1290 at these settings and got 51.2 average fps. I also did a run in Unigine running at 1920x1080 with x4AA x4AF Tessalation: Normal and Shaders: High I achieved a score of 1273 and 50 average frames. In 3dmark 11 at extreme preset I scored a Gpu Score of 1902. Btw should I overclock my memory because I heard that overclocking the memory doesn't really add that much performance.

My current overclock settings:
Core Clock: 1100
Voltage: 1.16
Memory: 1200
Power Limit(Target): +20%
I'm using ASUS GPU Tweak to increase the voltage and allow me to overclock past 1050 on the core.
I seem to be stable at the current overclock and was wondering If I should try and take it futher seeing as my GPU temps only really hit 55c in Uningine at the max, and I know that is a safe fps but I was thinking of running a custom water loop and overclocking more so my vrm doesn't get to hot. I have the Gigabyte windforce edition card which supplies great cooling but I think I may want to get a aftermarket cooler that provides better vrm cooling so I don't really have to worry about the vrm getting fried even though I have heard that 1.16v shouldn't fry it but I would rather be on the safe side anyways.