Proper CPU only watercooling for USA folks is $250 including shipping.
Most first time CPU only with good parts is closer to $300, especially if noise is a concern.
You won't find anything better for your CPU that anyone who knows anything about watercooling. The parts in that kit are stellar. One of the top 3 waterblocks, great basic pump, only Laing makes pumps worth their stuff for real watercooling.
BUT, the H50 might fit your needs if you go push pull on the fans and use room air, not warm case air.
Ahh NM, you want 4.0, so you need more AMD don't like hot temps.
Your moving into the big boy stuff, every bit more of cooling isn't linear in cost anymore.