Yes you will need the SATA connectors to connect your hard drives and the PCIe connector to connect a video card should you decide to upgrade in the future. You will only be able to run 2 IDE devices with most modern mobos but if your two optical drives are IDE and your new hard drives are SATA you're ok.
Yes a 480W PSU will run that (minimum 350W for your video card)
You might want to reconsider the AMD chip and motherboard. The Intel Core2Duos beat the AMD's hands down especially if you're planning on overclocking. There's also a bug with the AMD dual cores and AH where you will need to install a patch that will basically shut down one core while playing. That said people use them all the time.
Also, you do know that you can get a very highly rated WD 650 for $70 vs $50 ea. for the 320's right?
Finally, for a net $10 more after rebates the 9500 GT I posted above will out perform that PNY 8600 GT.
Other than that it looks ok. The links didn't work but I went and looked at each component on newegg. There were two M3A78-CM's though... one at $75 and the other at $50. Not sure which you were getting but they looked similar.
