I build hackintosh! I am selling a very stable and thoroughly tested system with 30 days support and a usb drive for recovery should you need it!. This system is runing Yosemite. This system is exactly like a 2013 Mac Pro and will give you similar performance with its Geforce 780 6gig card which is faster than anything available for mac.
Also selling my laptop that is same as macbookpro 2012, it dual boots win7 and osx mountain lion.
I can also build you a custom system on laptop or PC.