Why do you want lowest temp?
You want reliabilty then get air cooling. The answer is noctua. D15 (double tower) or single tower U14s. The d15 beats a lot of liquid coolers and the u14s isnt that much warmer.
It comes with a syringe of noctuas thermal paste.
Liquid coolers can leak, their pumps can fail (oh now your effed) and whats their lifespan regarding mounting kits? Will the manufacturer make an update for the model?
Nocuta will send it to you anywhere in the world for free. Their fans are guaranteed for 6 or 7 years.
TLDR - a big dumb block of metal with highest quality fan