What accessoiries do I require to properly run CoreELEC on the VIM3?

The VIM3 basic board looks very interesting as an HTPC solution with CoreELEC but I’m hoping to get some recommendations here regarding the accessories. I’m currently looking at:

  • VIM3 basic board
  • DIY case without metal plate
  • Heatsink
  • PSU (I will reuse an old 5V2A phone charger)

Do I have everything I need to run CoreELEC properly with those accessories? I’m concerned about heat so I have few questions:

  1. Is the heatsink sufficient without fan? I prefer passive cooling if possible because of noise and I don’t even see the fan listed on AliExpress.
  2. Is it necessary to add the heat pad and metal plate to the case in terms of passive cooling?

I will run my VIM3 in a room temperature of 20-25C degrees (Celsius) year-round btw.