If you don't buy the top end parts with your new machine it will be quite a bit quieter than your prior system because the power consumption has dropped a reasonable amount on todays machines. We also have bigger cases with larger fans and heatsinks that give more air flow for less RPMs, overall reducing the noise.
You could get a prebuilt water cooler for the CPU, but its not really worth it for quietness. First off they don't tend to win awards for quiet. Secondly they don't cool the noise producing monster in the case which is the GPU.
So lets say you do want a high end machine (3770, GTX 680) then to quiet both down you need a custom water loop. A custom loop allows you to choose how many fans you spread the cooling over, as a general rule a thick 120mm radiator slot will cool around 130W of power to 10C delta with an 800rpm fan, which is near on silent. So you would need 3 such slots to cool a top GPU and CPU, 2x120mm would do the job as well since you aren't overclocking. Combine that with a pump, tubing, barbs, block for CPU, block for GPU, reservoir and you'll notice one noise sticks out - the Hard disk. That rotation is seriously loud once you remove the big noise makers so you'll want to go full on SSD. Then the PSU becomes a concern and the easiest way to fix that is oversize it a little bit and buy a good quality one (efficient) so it rarely if ever spins the fan up below minimum. That would be quiet, but it'll cost you around £300 in all for the cooling and you'll need to choose your case so the radiators and pump etc will fit.
I do this and run 6x 120mm thick radiators for a grand total cooling capability well above 700Watts. I overclock my components to within an inch of their top capability and I manage to do so with fans running around 800 RPM. Its very quiet, but there is still a small amount of fan noise if you pay attention in a quiet house. Its not a problem amount of noise.