No, the cooler and clockrates matter much more.
Do you mean 2x8 or 4x8GB? Fitting 8 sticks into 4 slots would certainly be a noteworthy achievement.
Unless you want to go for a crazy overclock watercooling is never necessary and it that case you'd need a much more expensive mobo to even get there. You also can't afford it. All-in-ones are never recommended because they don't do shit. https://www.teamfortress.tv/12714/pc-build-thread/?page=19#555
Honestly do you even plan on overclocking? I'd just drop the cooler and use the free stock cooler. Maybe even drop the X because the 3600's performance is so similar anyway.
Not a fan of the PSU considering what you can get for the same price.
Or less if you don't use pcp because it sucks outside of the US. https://geizhals.de/evga-supernova-g3-550-550w-atx-220-g3-0550-y2-a1549684.html
2070 non-Super or 5700 XT are also options if you want to save a bit of money.