Double Check Wattage

Decchi

Honorable
Jan 18, 2013
10
0
10,510
Hi, yo, wassup, I'm building my first high end computer, where i've gotta deal with more then something you could pick up off the shelf. So, i'll start with specs:

ASUS Crosshair V formula-z
AMD FX-8350 AM3+ (Going to overclock to at least 4.5GHz)
ASUS GeForce GTX 550 ti x2 in SLI
Corsair Vengeance 8GB (2 x 4GB) x2 (16GB. Yes, I know it'd probably be better to use two 8GB or one 16GB, but the second set fell into my lap from a friend who didn't want it and i wasn't about to pass that up)
Cooler Master V8 heatsink/fan
Seagate 7200RPM 1TB SATA 6 Gb/s
Slot load CD/DVD Burner
Slot load Blu-ray Reader
ASUS PCE-N53 Dual Band N600 (PCIe x1)

I'm still on the fence about whether or not I'm going to use a soundcard (if i do, it'll be PCIe x1) and a TV tuner (PCIe x1 or USB), and i'll most likely throw a 600GB Velociraptor in there too. But all of this is gonna be in the Thermaltake Armor+ fullsize tower. Everything is going to be full wireless (keyboard, mouse, headset), but those don't draw off the powersupply as far as i know, but i'll throw it in for good measure.

Now to my question. I've been looking into power supplies, and have very quickly realized that section of my computer knowledge is lacking at best. But through fiddling around and reading here and there, I landed on the SeaSonic M12II 850W PSU. And as I look, i'm feeling confident that will be plenty, but i know the dangers of underpowering a computer and i can't afford to replace anything i might blow up, so i wanted to double check with people who know far more than i do. And I'd like a little leg room for the PSU for the occassional gadget (Like the USB powered missile launcher) I run across. Thanks for your time!
 

Decchi

Honorable
Jan 18, 2013
10
0
10,510
Also, and for curiosity's sake, further on down the road i'll probably go to water cooling. Would that set up require more? If i do, i'm going to run it over the GPU's and CPU.