Ive had a water cooled system before. It was pretty cool..but it does become a hassle when you need to change things out...seriously..if you get a new GPU..you need a new block...a new CPU..a new block. They have graphics cards that come with the blocks already on them...but they cost hella money.
You can save your 1500 you were going to spend on a kit and just get a regular computer.
I built a rig for 1700 and it runs just as cool as any watercooled system...just get a good heatsink!