As your using the case for database applications. This is my opinion. I'm no expert on this subject.
MY family owns a small company and have a "server" rig specifically for SQL and database. We have about 3,000 customer files on record and the rig is powered on and running 24/7. Its even on when the company is closed for holidays. We are running a i5 with 500W PSU 4GB RAM and a cheapo $40 graphics card. Your most important components are your Motherboard and PSU. These parts CAN NOT fail. Or you may end up with serious downtime. With you rig, you will most likely do fine with a 350W PSU. But I agree that the 500W corsair is a good choice.
I'm not familiar with the asrock motherboard and a quick look at it seems to indicate its a good choice.
I'm not too sure with what it is [asrock]. Buy you want to stay with anything that say's "gaming" on the box. "gaming motherbaords" aren't designed to last as long as "business" motherboards and generally work on a bang for buck basis rather than stability. Rather they come with long warranties to make up for their tendency to fail after several years.
As for the hard drive. You should stick to 7200 rpm hard drives. These are cheaper, more stable, and have higher capacity. SSD is a relatively new thing, and I'm not to confident about their stability. I'm not sure if their made to be left on 24/7 for years at a time. ALSO: For your hard driver. I think businesses typically prefer WD Caviar Green / blue. They run cooler and use less power for the trade off of lower write speed. I'm pretty sure you won't be dling gigabytes of pirated games like other black users soooo... jk I have a suspicion that lower power and lower right speed and cooler = more stability. I don't know if thats true.
As for a case.
I'm more familiar with mid-sized cases (for gaming and workstations). You should be searching for a compact case / server case. Since you won't be using a video card and need portability. NOTE: Your IEEE port and USB ports are on your Motherboard, not on the case. Your motherboard will come with a little plate which you pop onto the case.
This a good page for you to be looking at.http://www.newegg.com/Store/SubCategory ... er-Chassis
[Edit] Before our current server. We had a cheapo dell running it. We had a critical software failure in our database as well as a failure with our master server. (Old databdase was MSDos) And lets just say, no one in my family got much sleep at all for the next 2 weeks working 16hours a day. In a fix now or bankrupt and die scenario.