[Homebuilt] Advice on Upgrades

Hello all, A few years back I did my first PC build and while it has lasted me quite a while I am needing to do some upgrades to it. I've listed my specs below of what I currently have and am looking to buy a new Mobo, CPU, and if need be some Ram all while keeping the price tag under $200. Can anyone lend some kind suggestions? I will be upgrading to Windows 7 when I do this but that won't impact the $200 for parts.

Current Setup
MOBO: ASUS M2N32-SLI Deluxe Wireless Edition AM2 NVIDIA nForce 590 SLI MCP ATX AMD
CPU: AMD Athlon 64 X2 6400+ Windsor 3.2GHz Socket AM2 125W Dual-Core Processor ADX6400CZBOX
RAM: OCZ Reaper HPC Edition 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel
GPU: NVIDIA GeForce GTX 260


Potential Upgrades
MOBO: ASUS M5A97 LE R2.0 AM3+ AMD 970 SATA 6Gb/s USB 3.0 ATX AMD Motherboard with UEFI BIOS
CPU: AMD Phenom II X4 965 Black Edition Deneb 3.4GHz Socket AM3 125W Quad-Core Processor HDZ965FBGMBOX
Total Cost: $174.98