PCPartPicker part list:
http://pcpartpicker.com/p/3DTqB
Price breakdown by merchant: http://pcpartpicker.com/p/3DTqB/by_merchant/
Benchmarks: http://pcpartpicker.com/p/3DTqB/benchmarks/
CPU: Intel Core i7-4770S 3.1GHz Quad-Core Processor ($302.98 @ SuperBiiz)
CPU Cooler: Cooler Master GeminII M4 58.4 CFM Sleeve Bearing CPU Cooler ($34.98 @ OutletPC)
Motherboard: Gigabyte GA-H87N-WIFI Mini ITX LGA1150 Motherboard ($110.98 @ SuperBiiz)
Memory: Crucial Ballistix Tactical Tracer 8GB (2 x 4GB) DDR3-1600 Memory ($96.99 @ Newegg)
Storage: Samsung 840 EVO 1TB 2.5" Solid State Disk ($449.99 @ Amazon)
Video Card: EVGA GeForce GTX 780 Ti 3GB Superclocked ACX Video Card ($689.99 @ NCIX US)
Case: EVGA Hadron Mini ITX Tower Case w/500W Power Supply ($149.99 @ NCIX US)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) ($89.98 @ OutletPC)
Total: $1925.88
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-05-04 16:54 EDT-0400)
I would do some serious research to make sure that that 500w psu has enough amps to support a GTX780ti because it doesn't really have enough watts. Is that why you are so concerned with keeping the wattage as low as possible? Just get a more powerful psu and enjoy with no worries.