First you gotta learn about WC. It's not like walking into Best Buy.
Spend a while reading this info, get a feel for what your getting into and learn.
It’s not 'Roket Science', but
you need to know the basics and the lingo as a beginner.
You should spend a few hours on the listed sites reading threads, guides and more. It's how YOU learn. I can recommend the best stuff, but there are things only reading and participating on forums will ya learn anything. You don’t have to join all the forums. But reading ALL the WC stickies and many threads that interest you is important. A thread might be 50 replies long, and 15 of those replies might be what you needed to ‘PASS THE TEST’. Remember, once the $500 of goodies show up on your doorstep you’re on your own.
Also while there please read on case mods etc. The radiators do NOT fit in many cases. Reading up on pumps and hose routing, wire management and other things are important. Google your planned case and the word water-cooled in one line. You might get lucky.
For your benefit please spend a few days reading a LOT. It took me a while; I was big into Air over clocking and started to read about water-cooling. I made my decision to water-cool. THREE months later I made my first purchase of parts. Yes it took me that long and I have built a few systems and always just fine.
Don't expect miracles or SUPER DOOPER over clocks. Your temps with a good WC rig will be better than you could of got on air, guaranteed. What you will get is a quiet system that can handle OC to the max of your hardware IF you buy quality and buy smart. And minor maintenance too, a bonus for the water cooler.