Nice system. What videocard?
Anyway, I have a 780G, I don't watercool it even though it gets hot. Although I'm not as OC'd as you are. You might put a better heatsink on there then use a fan on that heatsink, or sure, give watercooling a shot. Personally I wouldn't watercool anything less than a top-of-the-line chipset though.
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ASRock M3A785GMH/128M
Phenom II X4 925c2 @ 2.80GHz (95W)
OCZ Platinum PC3-1333 2x2GB 7-7-7-21
WD5000AADS
Raidmax RX-500AF
Check it out.