You sir need a server. You're going to be hard pressed to build a dual socket motherboard "desktop" without spending as much as a used server. Get out your credit card, head to ebay, and keep an eye out for some HP G6/G7 servers. Expect to pay between 500-1000 for a good used one.
I just noticed the part about games. Here's the thing. If you're going to be hosting a database for your company then you need a real server. Real servers come with warranties and guarantees and such. You don't want to be liable for building your own and then having to support hardware failures. What you need to do is buy a server for the database/rendering and then buy a separate box for gaming.
EDIT: Man I'm bored today. So for the lols I priced out just a motherboard and the CPUs.
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131379&name=Server-Motherboards
http://www.newegg.com/Product/Product.aspx?Item=N82E16819117256&name=Processors-Servers
So you're at roughly $1600 with nothing but your mobo/cpus. In the long run buying both a server and a gaming PC will be cheaper.
No I don't need a server, I have one in the office for important crap.
This will be my full time workstation. Which I will use for gaming, graphic design, photo editing and 3D rendering.
What I meant by database. Is it will have all the info of all my clients, my workflow and my big 3d/graphic projects. Clients that are far away will be able to see progress on their project using TortoiseSVN.
The main reason for dual CPU is speed on rendering. Everything else is just like a normal PC.
And yeah i rather have one machine that covers all my needs.
First i did thin of maybe taking a loan and setting up a render farm/server and then rent server space.
But that is just too much hassle atm for me.
Here is one that i've built so far online:
Processor (CPU)
Intel? Xeon? 8-Core E5-2687W (3.1 GHz, 8.00 GT/s, 20M L3 Cache)
Motherboard
ASUS? P9X79 WS - SOCKET 2011, QUAD DDR3, USB 3.0, SATA 6 GB/s
Memory (RAM)
16GB KINGSTON HYPERX GENESIS QUAD-DDR3 1600MHz X.M.P(4 x 4GB KIT)
Graphics Card
2GB NVIDIA GEFORCE GTX 560 Ti - 2 DVI, HDMI, VGA - 3D (Special Offer)
Memory - 1st Hard Disk
120GB KINGSTON V+200 SSD, SATA 6 Gb (535MB/R, 460MB/W)
2nd Hard Disk
1TB WD CAVIAR GREEN WD10EARX, SATA 6 Gb/s, 64MB CACHE
But I would love to see if it is possible to do same but with 2 cpu's