Threw together the i5 based option quickly, single merchant is newegg to make ordering stuff easy (assumed a 1TB drive for storage, this can be changed to what you want, i.e. SSD only, SSD boot and HDD storage), this build leaves out OS and disc drive, OS is your choice but probably Win7or8 and 64bit to use the ram and disk drives are options that alot of ppl skip since they just use USB for everything or download
PCPartPicker part list:
http://pcpartpicker.com/p/QWfH8d
Price breakdown by merchant: http://pcpartpicker.com/p/QWfH8d/by_merchant/
Benchmarks: http://pcpartpicker.com/p/QWfH8d/benchmarks/
CPU: Intel Core i5-4440 3.1GHz Quad-Core Processor ($179.99 @ Newegg)
Motherboard: Gigabyte GA-Z97N-WIFI Mini ITX LGA1150 Motherboard ($127.55 @ Newegg)
Memory: Kingston HyperX 8GB (2 x 4GB) DDR3-1600 Memory ($86.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($54.99 @ Newegg)
Video Card: XFX Radeon R9 280X 3GB Black Edition Double Dissipation Video Card ($294.99 @ Newegg)
Case: BitFenix Prodigy (Black) Mini ITX Tower Case ($79.99 @ Newegg)
Power Supply: Corsair CX 600W 80+ Bronze Certified Semi-Modular ATX Power Supply ($59.99 @ Newegg)
Total: $859.49
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-06-07 14:02 EDT-0400)