air is easier, but water is better. custom made water cooling is quieter then pc case full of fans. one good 120x2x60mm (120mm size rads are recommended by most guys, better fan selection of this size available on the market and easier to fit in) radiator should be enough to cool down both cpu (even with some overclocking, not extreme) and gpu. pumps have flow regulators nowadays, manual or automatic (pwm) (high or low flow doesn't really effect cooling much, fans do), just like fans do, so they can run very quiet. there are also external types of radiators with no fans at all, but you will still need at least 2 fans in the case, motherboard need some air flow too.
my example here, was on the limited budget, so no water for gpu, maybe later i hope, that is why that rad is so huge lol my pc case don't have any windows, so looks doesn't matter much.
don't forget about dust filters, something like this: http://www.demcifilter.com/p0105/HAF-922-Dust-Filter-Kit.aspx