4x8 is cringe due to you basically being locked into dual-channel ram and resale purposes. Far easier to sell 2x16GB sticks than 4x8GB for the same reason 2x8GB is easier to sell than 4x4GB of DDR3.
For air cooler, minimum should be NHD14 and NHU12A if you can afford it. Otherwise bequiet dark rock pro 4 is an alternative.
The cheapest upgrade you can do right now is replace your current fans with noctua 120mm fans. Cooling performance will still be largely inadequate but will barely be good enough - hence the strong recommendation to add a Noctua fan in the earlier build.