Have you ever built a PC before?
Here are a list of the parts I plan on purchasing:
Car: 2005 Dodge SX 2.0
Case: Mini-Box VoomPC-2
CPU: Embedded VIA C3 1.2GHz
Motherboard: VIA EPIA-MII12000G
DVD: LG Slim DVD/CDRW Combo Drive
Memory: 512MB 240-Pin DDR SDRAM DDR2-533
Drives: 2.5" HD 60 GB Hard Drive
Wi-Fi: Buffalo WLI-CB-G54S
Antenna: 7dBi OMNI 10' Antenna MC-Card
Bluetooth: D-Link DBT-120
GPS Receiver: GlobalSat BU-353 USB
GPS Software: iGuidance v3.0
PSU: M2-ATX 160W
Internet: Portable Rogers Yahoo! Hi-Speed Internet
OBD-II: ElmScan 5 USB Scan Tool
What cables/wires must I purchase to hook this altogether?
Yes, I have many times.
You can find great info on how to hook up the power and speakers etc in the FAQ. You will need to think about how you are going to do those