I use an eisbaer LT 240. 25 rad but full copper, not aluminum like all the others. And you can also search for the non LT version and you will get a 30mm copper radiator.
I have a 3700x at 4.2 and 1.36v (more or less, I'm changing and tuning things all the time) I have low 40 to high 30s on idle and noctuas at 600rpm I see around 83 under full load at Intel burn maximum setting. Playing is more like 55-60 and rendering with vray doesn't go over 75.
In my sample the cold plate of the block was a bit curved and I got some improvements by lapping it. But appart from that very happy with it.