Question about Arctic Liquid Freezer II 420

Like the previous speakers, I can only recommend the Fractal Define 7 XL, plenty of space for these (or even two!) AIOs and even more fans.

The Fractal Meshify 2 XL accepts a 420mm radiator (or even a 480mm) according to the manual, just like the 7 XL mentioned above. The cases are quite similar. The Meshify focuses more on airflow and cooling temperatures, the Define on insulation and low noise.

I personally know of only one case where the manufacturer lists a 420mm radiator on the top in the compatibility. With the "Fractal Define 7 XL" you should be able to mount this radiator on top. Digitec also offers this case:
Fractal Define 7 XL (Big Tower)