As my current skill about hardware, I would in you case have picked up an i7, but if I understand your question right, you want either the Phenom or the Q9650. The s775 is reaching the end of their lives, and probably will the Phenom too in not too long time.
I must say that i am happy with the purchase, their nothing wrong with ebay, unless, your in overclocking or want higher quality parts.
This PC is much better at converting video then my old pc which was a core duo.
Hope this helps someone who can decide between the AMD phenom 955 or Intel quad Q9650.
Reason why I chosen Intel in the end is because Intel have always seem to be better at video encoding, then AMD although the AMD Phemon was tempting with its ddr3 memory & AM3 socket support. I choose Intel my choice I'll Live with that.