To my knowledge, the Power Supply used is just the common ATX form factor design.
Approximately 6 Inches Wide, 5-1/2 Inches Long, and 3-1/2 Inches Tall.
Needs these power cables;
A) 24-pin ATX main power cable
Newer power supply's come with a 20 + 4-pin ATX main power cable.http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain20plus4
That is so the power supply can be used on a motherboard, that needs a 20-pin, OR a 24-pin ATX main power cable.
B) 4-pin ATX +12 Volt power cable.
Often referred to as an ATX12V power cable.http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4
[Note color of power cable connectors does NOT matter ]
Note the Lock on the side of the power cable's connector, and matching Tab on the motherboard connector.
The 20 + 4-pin ATX main power cable, and matching motherboard connector; has this type of Lock/Tab also.
C) Needs at least 2 SATA power cables.
The Harddrive is a SATA unit, and I believe the optical drive (CD/DVD drive) is too.http://www.playtool.com/pages/psuconnectors/connectors.html#sata
Often has a Lock on the connector. Press to release when installing, or removing.
D) Should have at least two 4-pin (Standard) Peripheral power cables.
Misnomered as 'Molex',http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral
E) Needs one 4-pin (Small) Peripheral power cable, for the Card Reader.http://www.playtool.com/pages/psuconnectors/connectors.html#floppy
Also needs 300 Watts.
A Power Supply like this one would work,http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=899123&CatId=1079
For additional questions please post in a Comment.