You will definitely get a better build by buying your own parts and assembling them together. Before you start looking at parts, check these videos out teaching one to build a gaming computer:
Part1:
http://www.youtube.com/watch?v=lPIXAtNGGCw
Part2:
http://www.youtube.com/watch?v=d_56kyib-Ls&feature=related
Part3:
http://www.youtube.com/watch?v=RxaVBsXEiok&feature=related
They are very helpful to someone who is new with computers.
This is my computer suggestion for you:
CPU: Intel i7 2600k $315
http://www.amazon.com/Intel-BX80623I72600K-Core-i7-2600K-Processor/dp/B004EBUXSA
This is one of the better CPUs on the market. It is fully overclockable and has 4 cores. It can hyper thread and turn the 4 core CPU into 8 threads. This CPU is overkill and the i5 2500k is cheaper and gives similar performance, but with this, you don't have to worry about having to upgrade parts anytime soon.
Graphics: 2 x SAPPHIRE 11196-00-40G Radeon HD 7950 for CF $900
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102962
This is one of the best GPUs on the market, only surpassed by the HD 6990, gtx 590, and HD 7970. With 2 of these in CF mode, you won't have to worry about your system going out of date any time soon.
MoBo: ASRock Extreme 3 Z68 $122
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157271
This is an amazing motherboard for the price. It has 2 PCIe 3.0 slots which allows SLI and CF. It is also a z68 chipset allowing you to overclock your CPU if you want.
PSU: Antec EarthWatts Series EA-750 Green $85
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371051
This is a very reliable PSU from a reliable company. It is 750W, which is more than enough for your needs. It'll allow you to SLI or CF the graphics card AND OC the CPU without needing more power.
Case: NZXT Phantom PHAN-001BK Black $110
http://www.newegg.com/Product/Product.aspx?Item=N82E16811146068
This is an awesome looking case that happens to be full-tower too. This case is large enough for ALL your components and more.
HDD: Seagate Barracuda ST500DM002 500GB $85
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148767
This is just the storage drive. It is 500GB and is decently priced, if you require more room, then you can go with a 1TB drive.
SSD: Mushkin Enhanced Callisto Deluxe MKNSSDCL120GB $155
http://www.newegg.com/Product/Product.aspx?Item=N82E16820226152
This is the boot drive, it is supposed to hold Windows 7 and any applications that you use a lot such as Word and games.
RAM: Team Elite 8GB Memory Model TED38192M1333HC9DC $36
http://www.newegg.com/Product/Product.aspx?Item=N82E16820313086
This 8GB RAM is kit more than enough for what you need. It's from a reliable company and I highly doubt you'll even utilize 4 of the 8GB of RAM.
Heatsink+Fan: CM Hyper 212 EVO $35
http://www.newegg.com/Product/Product.aspx?Item=N82E16835103099
This is a great HSF for overclocking. It'll keep your CPU cool and is extremely decently priced.
DVD-ROM: LITE-ON DVD Burner $18
http://www.newegg.com/Product/Product.aspx?Item=N82E16827106289
This DVD burner is terrific, it has high ratings and is decently priced. If you are going to watch Blu-Ray movies, then go with a blu-ray drive.
OS: Windows 7 Home Premium 64bit $100
http://www.newegg.com/Product/Product.aspx?Item=N82E16832116986
Windows 7 as OS to do stuff...you must get 64bit in order to use all 8GB of RAM.
Total: $1961