not sure how much power i need:
asrock z77 extreme 4
G.skill Ripjaw Series (2x4gb) DDR3-1600
HD7850 or Similar
Tv Tuner Card 2250
Zalman Z9 Case
Samsung 830 128GB SSD
Samsung Spinpoint F3 1TB 7200RPM or Similar
Eventually I will overclock so I would need CPU cooler
Well, right now you are squarely in the 650W range, assuming a good quality power supply. It's that "or similar" following the HD7850 that makes me nervous though. Unless you are set on your graphics card, I'd suggest you up to 750W to cover a stronger graphics card, if necessary...plus room for future expansion.
I'd probably go with this:http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=927378&SRCCODE=GOOGLEBASE&cm_mmc_o=VRqCjC7BBTkwCjCECjCE
But you can get by with 650W OK if you actually go with the HD 7850.
Typically, you want to make a final decision on a video card and THEN pick your power supply.