AN35N Ultra ultimate gaming set up with windows vista

I recently have windows vista. I'm using a Shuttle AN35N Ultra as my base. I need to know what is the fastest CPU, best ghraphics card, and best memory\memorysetup I can support on this board. Any cooling and gaming boosting advice along to go with this would be cool. My rig is as follows.

Windows Vista Ultimate
Athlon xp(1.09 mhz)
ATI Radeon 9600
512 Crosair
WD Hard drive

I mostly just need to know to what limits I can take this mobo. Does anyone know if I can use an 8x agp card with this and if so which is the best one. NVidia or ATI? What are their new names if they have changed names. I know these cards are older.

Basically I need to give this rig a little boost.
Thanks

Well the reason for this is that I don't have that much money to spend and I mostly play counter strike source. Butt I think I can spend 300 to 350. I have a monitor and OS. What did you have in mind? I don't know anything I can do with that money. I run like 800X600, which I know is low but I don't mind it. Maybe I could bump it up a bit.