The system just for the proportion should be able to run gta 5 smooth with high graphics settings not the highest. And also the system is for software like Unity3d,Blender. And again i don'y need the highest graphics.
I prefer memories between 16-32gb.
I have already a case it's a mini tower not sure the model. What i do need is a new hardware: Cpu,memories,video card,motherboard. And make it as quite as possible.
I don't need a monitor,mouse,keyboards only the hardware it self.