Feedback on Current Workstation Builds

Hello everyone. I've been helping a local firm build new machines for their employees and I was hoping to get a little feedback and some suggestions to other options. I went through the part picker and selected what I've been using for builds.

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i3-2120 3.3GHz Dual-Core Processor ($118.79 @ Amazon)
Motherboard: ASRock H61M/U3S3 Micro ATX LGA1155 Motherboard ($66.99 @ Amazon)
Memory: G.Skill Ripjaws Series 4GB (2 x 2GB) DDR3-1333 Memory ($29.99 @ Newegg)
Storage: Seagate Barracuda 500GB 3.5" 7200RPM Internal Hard Drive ($58.98 @ Outlet PC)
Case: Cooler Master Centurion 5 ATX Mid Tower Case ($60.98 @ Newegg)
Power Supply: PC Power & Cooling Silencer MK III 400W 80 PLUS Bronze Certified ATX12V Power Supply ($62.98 @ Newegg)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($17.99 @ Newegg)
Operating System: Microsoft Windows 7 Professional SP1 (OEM) (64-bit) ($135.62 @ Outlet PC)
Other: Rosewill NEC 4+1 Port USB 2.0 PCI Card ($8.99)
Total: $561.31
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-02-13 11:20 EST-0500)

There are a few changes that I've made recently because I normally order everything from Newegg. Recently though, they have been out of the Antec EarthWatts Green EA-380D power supply that I normally prefer to use, so I switched to the PC Power & Cooling model. Also they have recently been out of stock with the Antec 300 Steel Case, which I prefer over the Centurion. Basically I'm just looking for suggestions for a law office environment. I know that 500GB drives might be overkill, but it's relatively cheap, so why not.

Ideally I would like to keep the total right around $550-$590 out the door. Again, with Newegg being the primary vendor.