Or at least, part of a new computer!! Woohoo!

Here's what happened in short. I had an Impervio-built OCZ SXS 500W power supply that went up in fabulous smoke. I had an Asrock A780GXE/128M motherboard (open-box from NewEgg) that joined it. So now I'm out a power supply and motherboard. The processor will be torn out but I have no way to verify if it's good or bad (I don't have another AM2 board to fudge around with). I'll put it like this: it died when booting with a fabulously disappointing load.
Athlon 64 3500+ Lima (45W)
Wintec AMPX 2x1GB DDR2 800 CL6
Asrock A780GXE/128M
Radeon HD 3200 IGP
Seasonic Barracuda 7200.7 160GB
Oh well. But it's time to replace what was lost. I have to build this machine and make sure it works, so I was thinking of different ways to do such. The first and foremost idea is to swap out my current main setup into this box with a new PSU. My normal PC's specs follow...
Pentium E2140 1.6GHz @ 3.2GHz
A-DATA Vitesta Extreme Edition 2x2GB DDR2 800 CL4
Abit IP35-E
Radeon HD 3850 256MB
2 x Western Digital Caviar SE16(/Blue) 320GB
Western Digital Caviar Black 1000GB
I was going to swap out the E2140 + IP35-E after ordering (and receiving, of course) a new motherboard and processor. I want top performance for <$300, including this graphics card...
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125251I will need a power supply, motherboard, and processor. Any ideas?