Computer Help!

[CluelessConman]

Hello! I've been researching into building my own computer only to find that I end up looking at parts that bust my budget. I've found what I think I need in the Dell XPS 8500. I was wondering if anyone could help me find parts to make a similar build and perhaps have it a bit cheaper. I'll put the Dell's specs below. If anyone is kind enough to help, I would really appreciate it!

OS: Windows® 7 Home Premium, 64Bit
Ram:8GB Dual Channel DDR3 1600MHz - 2 DIMMs
Hard Drive: 1TB 7200 RPM SATA Hard Drive 6.0 Gb/s
Graphics: NVIDIA® GeForce® GT 640 1GB GDDR5
CPU:3rd Generation Intel® Core™ i7-3770 processor (up to 3.90 GHz)
Monitor: Dell ST2220L 21.5" Widescreen Flat Panel LED Monitor
(I know i'm missing a motherboard on here, but the Dell site did not specify what is in the XPS 8500. Also, I was wondering if the graphics card is good. I'm new to making my own computer so I don't know what to look for in some of the parts. Thank you for your time!)

[prankstar]

that system is ok apart from the card personally i would got for a nvidia gt550ti or a gt 560 both of which are far better than the 640

[CluelessConman]

Thanks a bunch!