if all you want is decrease noise - then by all means, go for the watercooling kit.
however, if you just want to lower the temperature due to overclocking - just get a good heatsink and fan and use it. less hassle, less cash spent. of course temps will not be as low as a watercooling system, but there is no harm in running a processor at temps as high as 55c (during load).
dont believe me?
i run an amd 3600+ (2.4ghz, rock hard stable as in prime95 would give up before the system would

) and i can even hit 3800+ (2.5ghz) speeds with my 2500+ on MSI mobo with a slk900 and a thermaltake smartcase fanII. temps hover about 46c at 3600+ speeds and about 48c at 3800+ speeds.
and we are not talking loud here, just about 37db of noise... easily tolerable.