Need a new Mac Pro

I currently own 2 Mac Pro's, and 2 iMacs. I don't like the new Mac Pro as it is more of a workstation and less of a home PC for gaming etc... Will dual boot into Windows for non OSX Game Support.

I want to build a high end Mac Pro to replace my son's Mac Pro 2,1.

Budget is 2K+.

Current Specs that I have decided on.
Processor - i7-4770K
16G RAM
250G SSD
3TB Work Drive
Case - Cooler Master HAF XB

Questions?
Looking at motherboard GA-Z87MX-D3H
Is it worth upgrading? I have a choice on either a thunderbolt display (apple) or an older HDMI Apple 30" inch cinema display.

GPU - What is the best bang for the buck. 770? Should I utilize dual GPUs?

Any advice will be appreciated.

Thanks,

MWB

If you're aiming for a high-end build, you might consider whether you should go with an ATX motherboard (more PCIe slots) rather than the mATX motherboard you've listed. As far as I'm aware, dual GPU cards would only function as two discrete cards under MacOS, but search this website for the latest information.

For "best bang for buck" gfx cards see http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107-8.html

You can use 2 cards in SLI or crossfire with windows, but OS X will see the cards as separate - SLI/Crossfire doesn't work.