New
#11
Okay. My favorite vendor is Newegg, but they're not always the best deal.
CPU:
Newegg.com - AMD Phenom II X4 965 Black Edition Deneb 3.4GHz Socket AM3 125W Quad-Core Processor HDZ965FBGMBOX
Motherboard:
Newegg.com - ASRock 770iCafe AM3+ AMD 770 ATX AMD Motherboard
(A semi-random choice. Cheaper ones use the old nVidia 7025 chipset; I'd give that a miss. This one is also full ATX.)
RAM:
There are many makes at about the same price. This one is probably good:
Newegg.com - G.SKILL NS 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL9D-4GBNS
Most 2 X 2 GB DDR3-1333 1.5V would work well. Asrock publishes a Qualified Vendor List, but I don't see the part numbers at Newegg. (The QVL is sometimes out of date.)
Graphics card:
Newegg.com - SAPPHIRE 11192-22-20G Radeon HD 6670 1GB 128-bit DDR3 PCI Express 2.1 x16 HDCP Ready Video Card
Sometimes I'll get stuff from Amazon to avoid shipping charges.
I hope that you don't end up needing a new case and power supply. If you get a new PSU, though, I'd suggest a better graphics card, one that uses auxiliary PCI-E power. (Slippery slope.)