PSU advice for server build

Jan 30, 2003
Hi [H] PSU experts,
I'm working on putting together a home server/NAS/Plex server with the following specs -

2x Xeon e5-2670
Server motherboard (Currently planning on a Supermicro board, may swap out, but expect power draw would be similar)
8x8gb ECC DDR3 found a deal on another 8 sticks, so this may double)
8x6tb drives - mix of NAS/enterprise drives, mostly 7200rpm but a few 57-5900rpm drives
1xSSD cache drive
1xAMD HD6450 for HTPC functionality
1xDell SAS card (Flashing to LSI card)
Variety of fans in a Silverstone GD08 case

I'd like to have the option of adding a couple of extra drives down the line, and to upgrade the video card down the road if I decide to do so (though likely will never really put a true gaming card in this). I've tried a couple PSU calculators online and got recs ranging from a ~600W-750W PSU, so in trying to leave myself some headroom, was looking primarily at two models (both 80 Plus Platinum... I know there are folks that don't care, including [H]). Both are modular and well reviewed.

- EVGA SuperNOVA P2 850W (220-P2-0850-X1)
- CORSAIR HXi HX1000i 1000W

Any thoughts? The price difference after sales/rebates is only ~$20, so was leaning the higher rated 1000W model, just to leave myself more optionality down the road. Is that overkill? Will it use materially more power just by having more idle capacity?

Would anyone recommend something completely different for some reason? Thanks!