I suppose you could do rendering with a CPU or a GPU.
Which program will you be using to do the rendering.
I thought since you said light gaming that a high powered GPU was not a huge priority.
I can easily rework these with a better GPU if you want.
Do you need a OS?
How much storage do you need?
I have built 3291 computers (and counting) and I still can't enter a CD key correctly the first time.
The 5 rules of acquisition: