What kind of board is the Asus Maximus V Gene, high-end or regular?

Ignore the PSU calculator and tell me your specs.
I'd think high-end, but that calculator isn't accurate: you can often go with a lower wattage with a good-quality unit.

the mobo power consumption is only applicable usually if its comparing micro atx to atx, even so its pretty small. the extremevision(?) psu calculator is more accurate.

my specs:
Asus Maximus V Gene
Intel core i5-3550
HIS Radeon HD 6850 IceQ X Turbo Video Card - 1GB- PCIe 2.1- overclocked
Thermaltake V3 AMD edition- 2 red led 120mm fans
Corsair 4GB ram(2x2GB)
Intel Centrino Ultimate-N 6300
1TB HDD- 7200rpm
160GB boot drive HDD- 7200rpm
24x DVDRW drive
and I'll be runing windows 7

I'll most likely add Asus/Intel Thunderbolt, and add 2 more 120mm red led fans, and possibly upgrade my gpu in the future.

a 650w-700w psu will do enough(possibly 600w as well but i dont know how thunderbolt goes into power consumption) as ivy bridge consumes less watts and the 6850 is a mid range card. though are you sure your mobo supports thunderbolt, i personally have minimal knowledge of what it requires.

I also recommend that if you crossfire 2 6850s, and you have a spare 6 pin power connector left, the 2nd 6850 should be a sapphire toxic 6850(if you can find one), only because it can take the heat off the his iceq fans and spew it from the back. though this is just if you want minimal temperatures in the future.

I'll be pushing budget with the power supply. Crossfire will be a later upgrade. The mobo is one of the new Asus z77 boards, I'm sure it'll support Thunderbolt, I'll check again and see.

http://www.tomshardware.com/reviews/thunderbolt-perform...

this msi one is the only one i know of that has a thunderbolt port

The Maximus V Gene has a PCIe x4 slot, which can be used for the Thunderbolt PCIex4 card and the mobo has the Thunderbolt header.

All Asus Z77 boards have a TB header other than the Premium board which has a built in port. The add in TB card will be around $200.

Also, when the Maximus V Extreme is released, it will have a TB port.

That single-6850 machine will be fine on a Corsair 430W. You should prepare for two cards, though, with a 600W box. http://www.guru3d.com/article/radeon-hd-6850-6870-cross...

So I need about a 600W power supply?

Would a 550W work? Or even a 500W?

A 500W would probably be OK, but I think it's worth going 600W for two cards.