Fantastic choice of power supply and CPU.
Do you actually want a cube case like this?
Consider a home theatre case that looks more like an amplifier and will fit in your entertainment unit.
Silverstone makes some nice home theatre cases like the GD04 or GD05.
This also allows you to install a second hard drive if you want.
You can have a micro-ATX motherboard in these cases too, which is cheaper than mini-ITX.
Be careful of CPU cooler choice with some cases.
The stock intel cooler is more than adequate and I don't think the after market cooler will substantially lower noise.
4GB of RAM would be plenty.
You can go to a 2TB hard drive easily, but be careful above this as you will need to get UEFI boot working on both the Windows DVD and later for the hard drive to have a boot drive over 2TB.