I should have mentioned that the deal I posted is good for people going the normal PSU route. Of course server psu's can be cheaper. I have been researching them, but there seems to be too many variables to work out, or I'm overcomplicating things. Most every full guide I see shows using a 750w psu. I need my ants running at max gh/s no matter the extra cost of power because my power is cheap. And the 750 won't allow me to run 2 fully oc'd.
You can use IBM 2000w which is cheap again and very easy to use. Its server again psu but than u can run 4 s1 on one psu.
I can confirm as many as 6 running on the IBM DPS-2000BB. All of mine are OC'd to 393 and have been running this way for nearly a month. The supply has an input rating of 13.5A and I've measured the current draw at the breaker to be 10A. So 6 OC'd ants are a good number for this supply.
Here's all the info you need to get started with one,
https://litecointalk.org/index.php?topic=5854.0