Which Processor?

I looking to build a workstation for my son who's working with Poser 7, Vue 6 and Adobe Premiere and looking for any suggestions on what to put into it, especially the cpu. Rendering speed is high on the list, and your input would be greatly appreciated.
PS I'm trying to keep the workstation under $3000 or looking at 2 systems for multi-rendering.

Holy canoli dude, the sky is the limit with a $3000 budget if you're going to build yourself. Rendering speed is high? Well, the more cache on the CPU, the better - why not look at something in the high end QX series (The QX9650 is what I have for reference). Also, video card - you could spend all the money on a Quatro, or you could buy a really high end geforce (or multiple geforces) for SLI, or mod a single geforce in to a quatro - they're basically the same anyway, minus the rendering stuff in the quatro drivers that make them excel for it...

Thanks for the info! I looked into the Qx9650 and will probably go with it.