Awesome. I was planning on buying an Arctic accelero 3 to run with a pair of NF-F12 fans. Right now the blower card maxes around 83c at stock levels.
The FE coolers are designed to target around 84C max. However, the thing to pay attention to is what clocks are you seeing while hitting those temps.
Chapeau is very correct in that better cooling for the GPU will affect the GPUs boost ability. It can be the difference in you running at 83-84C at ~1800Mhz or 70C at ~2000Mhz. As for the CPU, you can pretty much have a reasonable cooler on it and OC it with good results as long as you stay within a decent temperature range.
EDIT:
However, keep in mind that a CPU running at 5GHz on a 240mm AIO vs 4.5GHz on a 120mm AIO can make a big difference for certain games depending on the situation.