AIOs/CLCs are not really any extra effort and they run nice and cool. I forget if you're going Intel or AMD but I do not recommend using an Intel CPU without a good 240 or 280mm AIO anymore because frankly Intel CPUs run incredibly hot. AMD CPUs run cooler, but with their XFR2 technology working very similar to Nvidia's GPU Boost the cooler your CPU is the faster it will run.

Just get an AIO with a 6th Gen Asetek pump. This particular AIO is the only 280mm with a 6th gen pump. https://www.corsair.com/ww/en/Catego.../CW-9060032-WW
This is the 360mm with the same pump. https://www.corsair.com/ww/en/Catego.../CW-9060031-WW
And here's the 120mm if you don't have room for the larger units, but you're probably better off buying a MASSIVE air cooler than a 120mm for CPUs in particular. https://www.corsair.com/ww/en/Catego.../CW-9060036-WW

The reason you want a 6th gen Asetek pump and not anything else is the big selling point on the 6th gen pump is reliability and so far only these products have a 6th gen pump.

Also don't bother putting an AIO on a GPU, GPUs run much cooler than CPUs thanks to their big massive heat syncs and better thermal conductivity.