Hate to tell you this, but today's onboard video is better than a 6450.
We would really prefer if you can get the PSU, optical, and hard drive brands/models.
Why don't you just upgrade the CPU and ram? Your mobo supports modern processors.
AMD Athlon II X4 640 Propus 3.0GHz Socket AM3 95W Quad-Core Desktop Processor ADX640WFGMBOX - Newegg.com
Crucial 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model CT2KIT25664AA800 - Newegg.com