PSU

I was using this PSU calculator on the net and it told me I needed just shy of a 900 watt PSU. can anyone confirm this? It seems like a lot but ive been wrong before. The system I will be building is as follows:

cpu: AMD Phenom II X4 965 Black Edition Deneb 3.4GHz Socket AM3 125W Quad-Core Processor HDZ965FBGMBOX

mobo: MSI NF980-G65 AM3 NVIDIA nForce 980a SLI HDMI ATX AMD Motherboard

ram: OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model OCZ3P1333LV4GK

video card: EVGA 768-P3-1360-TR GeForce GTX 460 (Fermi) 768MB 192-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card

hard drives: Western Digital WD15EARS 1.5TB Caviar Green and Western Digital WD10EARS 1TB Caviar Green

case: Ultra M923 Large-Tower ATX Case (has fan controller, lcd display, 3 120mm fans)

optical drive: LG IDE 16x DVD RW

speakers: Logitech Z-5 (which are USB powered)

Any advice greatly appreciated! thanks!