Which PSU for this system?

[Chromodar]

My old system died after 6 years of service. Here's what I'm looking at now:

Nanoxia Deep Silence 1
ASUS Maximus V Formula
Intel Core i7-3770K
Cooler Master Hyper 212 Evo
ASUS GeForce GTX670 DirectCU II Top
Samsung 840 Pro 256GB

Trying to figure out if I can fit a new storage disk in the budget, or if I have to stick with the newest of my current disks, and this partly depends how much money I end up spending on the PSU. As you can probably tell, temperature and noise levels are relatively important to me.
I plan to moderately overclock when I get the system, and when I start feeling like I need more power, I'll add water cooling and give it a more thorough treatment. I'd also like to have power to spare for a second GTX670. Eventually I'll be getting a second SSD exclusively for the OS too, but that should be a very minor impact on power requirements.
It's not really that big of a problem using the old storage disk, and if I go this route there's quite a bit of money to spend on the PSU. Of course, since I already went a bit stupid with the mobo (because I like the combination cooling, onboard sound and general featureset), there's no reason to pay out the wazoo for not much extra benefit.

There it is. I'm open to suggestions, advice and recommendations.

 

[Norlag]

You should only need about 500 watts. I recommend the seasonic S12II 520. Seasonic is the best brand for psus, so you really can't go wrong. You're looking at about a $65 price point for this particular model. Just make sure you get a psu that is at least 80+ bronze, it'll pay off.

 

[shortstuff_mt]

The OP stated he would like the option of adding another GTX670 in the future. You will want a quality 750W PSU for that headroom. This is the one I would suggest:

Corsair HX750
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010 $129.99

I've used Corsair HX series power supplies in a number of builds and have never been disappointed. Being modular helps quite a bit with power cable routing in a build.

 

[Norlag]

The OP stated he would like the option of adding another GTX670 in the future. You will want a quality 750W PSU for that headroom. This is the one I would suggest:

Corsair HX750
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010 $129.99

I've used Corsair HX series power supplies in a number of builds and have never been disappointed. Being modular helps quite a bit with power cable routing in a build.

Ahh thanks for pointing that out. I guess that means he can't afford the hard drive in his budget.

 

[shortstuff_mt]

Ahh thanks for pointing that out. I guess that means he can't afford the hard drive in his budget.

That may be true, but the PSU is the one component to NEVER scrimp on. I wouldn't settle for anything less than an 80+ Gold certified 750W PSU from a reputable manufacturer to power all those expensive components. Having a low quality PSU fry your expensive computer is a mistake you'll only make once...

Edit: Norlag, you obviously recognize the importance of a quality PSU based on your suggestion. I just want to drive the point home with the OP.

 

[Chromodar]

Corsair HX750
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010 $129.99

Modular, good reviews, 7 year warranty. That looks like a strong contender for sure.

Edit: Either I'm scatterbrained, going blind, or the select best answer button is hiding