Low Cost WAMP server

Hello all,

This is my first post and I would like your opinion on the small WAAMP server computer I am building for use in my database classes and to develop and test database designs. I need the computer in the next week and I want to order it in the next 24hours. Let me know what you think of the processor choice. I am hoping the AMD Sempron 45W is going to be fast enough for what I need. I want to stick to an AM3 socket and DDR3 memory in case I want to use multi-core AM3 processors. Will a 550W PSU be enough for 3 1TB hard drives? Thanks again for your opinions and if I am completely off the mark with a Sempron processor or anything, please let me know. Thanks!

APPROXIMATE PURCHASE DATE: Next 24 hours or so.
BUDGET RANGE: $150-$300 Before Rebates

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: The primary use for this would be to run a WAAMP server for a student learning mysql, php, sql and using dreamweaver, photoshop.

PARTS NOT REQUIRED: I don't need a keyboard/mouse, display as I will be using a KVM switch. I am going to use WIN 7 RC 64bit. No Hard drive needed I have a spare 7200rpm 500GB WD. I am also re-using a 550W PSU that I purchased a few months ago.

PREFERRED WEBSITE(S) FOR PARTS: Newegg
COUNTRY OF ORIGIN: USA

PARTS PREFERENCES: I just need a small case for the micro ATX mobo. Low power PSU since I will not be driving a graphics card. 3 hard drives tops, but I am starting with one 500GB 7200 rpm WD drive.

OVERCLOCKING: Yes / No / Maybe SLI OR CROSSFIRE: no overclocking and no video card since the MOBO should have built in graphics.

MONITOR RESOLUTION: 1280X1024

ADDITIONAL COMMENTS: I am building a low power, quiet computer to learn database design and then use the computer to host the WAAMP suite so I can design and test.

Here is what I have to Date:

ASRock M3A785GMH/128M AM3 AMD 785G HDMI Micro ATX AMD Motherboard
[url=http://www.newegg.com/Product/Product.aspx?Item=N82E16813157168][/url]

AMD Sempron 140 Sargas 2.7GHz Socket AM3 45W Single-Core Processor Model SDX140HBGQBOX
[url=http://www.newegg.com/Product/Product.aspx?Item=N82E16819103698][/url]

Crucial 1GB 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Desktop Memory Model CT12864BA1339
[url=http://www.newegg.com/Product/Product.aspx?Item=N82E16820148196][/url]

APEX TX-381-C Black Steel Micro ATX Tower Computer Case
http://www.newegg.com/Product/Product.aspx?Item=N82E16811154094