Water cooling is great if you need superior cooling for overclocking or something similiar, but I don't suggest it "just to have" or anything.
DangerDen makes good waterblocks, but I'm not up on most of the newer brands. Usually people make their own custom kits, and but the pieces individually. With affordable kits, you are likely to get a weak pump and aluminum blocks (not good)
Some decent kits :
Evercool WC-202 Watercooling Kit
TITAN Bianca TWC-A05 Watercooling Kit