Asking for Built!!!!!!

$400? That is a tight budget!
For a server, perhaps
PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i5-3350P 3.1GHz Quad-Core Processor ($179.99 @ Newegg)
Motherboard: ASRock B75M-GL Micro ATX LGA1155 Motherboard ($67.55 @ Newegg)
Memory: G.Skill Value 8GB (2 x 4GB) DDR3-1600 Memory ($47.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive
Case: Zalman Z5 ATX Mid Tower Case ($25.98 @ Newegg)
Power Supply: Antec EarthWatts Green 380W 80 PLUS Bronze Certified ATX12V / EPS12V Power Supply ($39.99 @ Newegg)
Total: $361.50
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-02-26 19:14 EST-0500)

assuming that it does not need to do any graphic rendering.

I do not know what a minecraft server entails. If it requires graphical rendering then a bigger budget is needed.
 
This is such a sweet build.
Could you possibly find stuff from Amazon????
Just trying to buy parts from there.

And Question. Let say i'm going to upgrade This pc to Gaming rig.

Am i be able to run decent graphic game if i buy Gtx 650ti and More powerful PSU?

Thanks for your help!
 
ASRock LGA 1155 Intel B75 SATA 6Gb/s USB 3.0 Micro ATX Intel Motherboard B75M-DGS
I choese mother board as that one

and Case
Cooler Master Elite 120 Advanced - Mini-ITX Computer Case with USB 3.0 Ports and Long Video Card Support (RC-120A-KKN1)
this one. is it good?
also i added Driver
Asus 24xDVD-RW Serial ATA Internal OEM Drive DRW-24B1ST (Black)

And What os do i have to choose