550$ build, prepare for my stupid questions

Hi guys, this is my first time doing a build. 

First, my needs. I tend to play APB: Reloaded, GTA IV, Battlefield, and TF2. I don't want anything crazy, but I want a good build that will get the job done for the money. I also record my gameplay with fraps a lot, so I'd like a good amount of HD space. 

 

 

I wanted a good build on a budget. I liked Syndicate's [url=http://teksyndicate.com/videos/build-best-550-pc-nov-dec-2012] article on a cheap $550 gaming rig[/url]. 

Question is, is the parts list ALL I need? Do I need a buy a heatsink or sound card or anything else?

 

 

ALSO, If I decide to make my own parts list from scratch, where do I start? How do I tell that all my parts will be compatible with each other? 

http://pcpartpicker.com

It'll even tell you if stuff is compatible.

 

 

After some consultation from /r/buildapc, it's come to this. Am I getting the most for my money?

 

PCPartPicker part list: http://pcpartpicker.com/p/tlJN
Price breakdown by merchant: http://pcpartpicker.com/p/tlJN/by_merchant/
Benchmarks: http://pcpartpicker.com/p/tlJN/benchmarks/

CPU: AMD FX-6300 3.5GHz 6-Core Processor ($129.99 @ Amazon)
CPU Cooler: Thermaltake CLP0579 72.1 CFM CPU Cooler ($19.99 @ Newegg)
Motherboard: MSI 970A-G46 ATX AM3+ Motherboard ($73.99 @ SuperBiiz)
Memory: Crucial Ballistix sport 8GB (2 x 4GB) DDR3-1333 Memory ($36.78 @ B&H)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($64.99 @ NCIX US)
Video Card: XFX Radeon HD 7870 2GB Video Card ($219.99 @ Newegg)
Case: NZXT Source 210 (Black) ATX Mid Tower Case ($38.99 @ SuperBiiz)
Power Supply: Rosewill Green 530W 80 PLUS Certified ATX12V / EPS12V Power Supply ($49.99 @ Amazon)
Monitor: Asus VS228H-P 21.5" Monitor ($138.99 @ Amazon)
Keyboard: Microsoft SIDEWINDER X4 Wired Gaming Keyboard ($49.99 @ Newegg)
Total: $823.69
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2012-12-20 09:10 EST-0500)

Switch out to a FX4300, save yourself $10 and they perform equal in gaming(2-10fps difference) here is the comparison, games are at the bottom : http://www.anandtech.com/bench/Product/699?vs=700

For BF3, the GTX660 gets better fps at various resolutions vs the 7870, here you can see the fps differences of both cards at various resolutions in various games: http://www.anandtech.com/bench/Product/548?vs=660

Right now you can get a GTX660 for $199, that is a few more dollars saved right there as well.

Instead of that Rosewill green, opt for a XFX PRO 550, it has more amps on the 12v rail it has a longer warranty(5 years vs rosewill 2 years) and it is the same price. It is the better deal in this case and it is a solid power supply.