first off and foremost,
RAM, corsair value isn't really going to be up to much (even though 2.7Ghz is good). See if you can get hold of couple of sticks of XMS 3200C2PT, that should be able to get up to about 2.8. If you can, try and increase the DIMM voltage a bit if you can as this usually does wonders. Next up, a better cooler may be in order, perhaps the EVO-120 AK-920. It's a great cooler and even with some AS5, it's still cool to the touch at the base where the
CPU is! And that's on an overclocked system like mine (it only gets to about 40 degrees Celsius when it's under load, such as BF2 or FarCry and at idle, it's reporting 33 degrees Celsius, and stable, although mines an athlon64, not an opteron). What makes it even better though, is that when it's the 'correct' way round (with the heat fins towards the back of the case), is that it's at the right point for an 80mm or a 120mm fan to be located as a case fan. This makes it as close to water cooling as you can get without spending £200+. I managed to find it for about £30 including VAT, but i can't remember where. It comes with a fan controller backplate and when it's set to low, it's inaudible, when at full, you can't hear it over the bangs and crashes of the battlefield, i have it at full almost all the time, and it's not exactly quiet, but it's not too loud. It's quite an extreme cooling solution, and in both mine and your case, for an extreme system.
HTH