Building a Graphic Workstation... but want good gaming too.

Hello Everyone,

I'm looking to build a new system but the market and the way products are rated has changed a ton since I last built a system maybe 5 years ago. My primary interest is creating a system that won't need to be upgraded for hopefully two years, and then when the time comes is easily upgraded for a relatively cheap price. My goal for the machine is to have quick test renders of complex 3d scenes, while still allowing myself the ability to work on other projects in the background. I'd also like to have good gaming, if not great, for my spare time.

I have approximately $2,500-$3,000 saved to spend on the system.

One question I have is the difference between Multi-core Xeon processors and the Intel Core2 processors. In the benchmarks on this site it appears the Core2's perform slightly better at equal speeds, and the hardware to use them is cheaper... such as motherboards and what not. What are the advantages of Xeon Processors if any?

My current thought is that since Core2 processors cannot run in dual, that using 2 Xeon dual cores would allow for a cheaper upgrade in the future from 4 to 8 cores as more products support multi-threading.

The second question is about graphics cards in relation to rendering and gaming. I know that Nvidia has a line of graphics cards called Quadro that is for workstations, but it seems that the only thing they have going is multimonitor support. Would there be a reason to choose a quadro over a Geforce 8800?

The system I'm looking to build would have 4 gigs of RAM(I would get more but read unless you use a 64bit operating system it doesn't use it?), 500-750gb of hard drive space, possibly a GeForce 8800 gts. Sounds not an issue to me so stock on motherboard or a cheap card is fine, unless somehow it affects performance. If anyone could point me in the right direction to further research before I buy that would be great! Thanks again.