Time for an upgrade!

Hi, I've decided it's time to start thinking about the upgrade, and I'll be taking a step up from my SY-K7V DRAGON Plus! "http://www.soyogroup.com/products/proddesc.php?id=37"
I've had this on my pc for about four years, and haven't really had to worry about much (hassle free) but now it's time for me to think about the future. I can't put any good video cards in here because it has One Universal AGP Pro slot (supports 1x/2x/4x modes), I'm looking to go up to at least 8x because I mostly want my computer to perform well for gaming, although I use it for everything. I'm willing to think about a processor upgrade (currently running an unclocked AMD Athlon 1.25 ghz) along with the video card upgrade over the next 3-6 months. I'm willing to go from around $125-200 for the mobo and I would love suggestions for all price ranges and for the video card and processor package. Super Sweet, thanks in advance!

Newegg.com offers a sempron 2900+ Mobo combo for $129, I like ATI cards but NVidia is buying USA. try an ATI 9800 Pro, it's a good mid range card, get a good power supply too, no point in good hardware if it's unstable from a crappy PS, try Antec, Enermax ect. New egg also sells a Antec case and 350W quiet power supply for $69. Another alternative is to shell out more money and get an Athlon 64. it's the best at playing games.

Super awesome, I like this deal. Any other suggestions for going 64bit?
I appreciate the help!