Upgrades to 6 year old homebuild

Hello Everyone,

I built by PC a while back (2006/2007). At the time, it was decent enough to get me by but I now want to convert it to an HTPC. As it currently sits, here is the configuration:
GIGABYTE GA-M59SLI-S5 AM2 NVIDIA nForce 590 SLI MCP ATX AMD Motherboard
AMD Athlon 64 X2 3800+ Windsor 2.0GHz Socket AM2 89W Dual-Core Processor ADA3800CUBOX
XFX PVT73GUGF3 GeForce 7600GT 256MB 128-bit GDDR3 PCI Express x16 SLI Support Video Card
Patriot Extreme Performance 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model PDC24G6400ELK

I want to upgrade it (hopefully) with minimal cost and effort. The two items I'm looking at adding are:
EVGA 01G-P3-1430-LR GeForce GT 430 (Fermi) 1GB 128-bit DDR3 PCI Express 2.0 x16 HDCP Ready Video Card
Intel PWLA8391GT PRO/1000 GT Desktop Adapter 10/ 100/ 1000Mbps PCI 1 x RJ45 - OEM

Can anyone advise as to whether or not these are good choices for the money, what other upgrades may be more beneficial, and of course, will there be any known compatibility issues with my current set up.

I appreciate the help!