Building a Computer For Blender To Run On

Hello i am new to this forum and i have a question…

i have about 1000-1200 dollars to spend on a computer to run blender on.

I plan to run ubuntu 64bit with blender and also yafray

i found some distros of blender and yafray for 64bit processors.

now all i need to do is find out which hardware would be best in my situation. any and all suggestions as to what hardware runs best with the above software would be appreciated.

I know that certain motherboards and processors work better with ubuntu than others due to drivers being available.

It would be nice to know which hardware has the least amount of problems to setup with the above software and also is the most compatible with the above software.

Thanks in advance for any hint/tips/suggestions

Socket AM2 A64 Dualcore (X2 4800+)
4GB of DDR2 RAM
nforce500 chipset motherboard
Nvidia graphics card (much better linux opengl performance): Geforce 7600GT.
2x 160GB HDD RAID0