If you want portability, consider this - Silverstone PS08B (Black), saves you a bit of money too.
You could also look into ITX cases/motherboards, but in terms of cost they tend to be awkward.
Also, the advantage of the APUs is cost. They are excellent value for entry level gaming, but if you spend that much on a motherboard it destroys the cost advantage, try something like a ASRock FM2A75M-DGS (around $55). You did get 1866Mhz ram though, which is definitely a good choice for APUs.
Don't use a Caviar Green drive, they are energy saving slower speed devices. If you want WD, look at Caviar Blue/Black.
With PSUs, it's hard to ignore the CX430, newegg is selling them at $20, great value.