I got around 400W - 450W on somewhat maximum load, with a power supply calculator. Note that this was calculated without adding in any fans, any devices using usb ports, any aftermarket cooling, or any overclocked components. This is just a rough estimate of how much power your computer will need. I would suggest looking at different power supply calculators and try them out to see what you get.
Western Digital WD Blue WD10EZEX 1TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive Bare Drive - OEM: 9.5 Watts
Corsair Neutron Series GTX 2.5" 120GB SATA III Internal Solid State Drive (SSD): 0.35 Watts
Corsair Obsidian 750D Black ATX Full Tower Computer Case: 27 Watts
Total: 381.45 Watts
As long as the PSU has a maximum combined +12 Volt continuous current rating of 34 Amps or greater and has at least one 6-pin and one 8-pin PCI Express supplementary power connectors then it should be able to do the job.