CPU 4200, now 4000, very few in stock, about 450 yuan
For motherboard, you can choose: ASUS, if the price is good, use Hummer!
Memory ：Kingston 1G*2
Hard drive: 160G
Graphics card: A card 2600XT Shenge (A card is great for playing games)
Power supply: Choose a better 350W
Monitor: 19mm wide, choose your own!
The above is basically done for 4,000 yuan. I just renovated one and it feels ok!