user3773: i went to configmyrig.com and selected the options to hit something close to 5mh.
here is a screenshot:
http://s28.postimg.org/uayj19exp/Screen_Shot_2014_01_09_at_11_21_58_PM.png
i'll be scrypt mining at a multipool and the total that came up for the complete setup is about $5,000 seems like alot but let me know if you have any suggestions. What i'm wondering is how many PSU's would I will need and what kind is recommended? I'm thinking it would be a gold or platinum for the PSUs but i'm not sure how many and what kind would suit 6 Radeon R9 290x's. Also is the motherboard & cpu selected good enough? I'll be using a milk carton for the rig instead of a case so i'll need to get a hold of a good one.

user11862: 
What i'm wondering is how many PSU's would I will need and what kind is recommended? 

I would recommend much higher PSU, at least 1000 Watt PSU for each two Radeon's R9 290x. This is based on some recommendations I found (here and here). I am 99.99% confident a single 750 Watt PSU will NOT be able to cover 6 GPUs of that power. 
I also think the motherboard you selected can only take 3 cards, you need to double check. Even with 3 slots the cards may not have enough room between the slots, so you will need to use extension cables. The CPU is actually overpowered, I would select a low-power one. CPU will not be used for mining. Memory is not used as well. You will be covered with a 2-4GB stick to run the OS processes.
No one seem to be bothered with a case. For that much price of a hardware you don't want much dust to come in. Or any morning coffee spilt on your expensive hardware... I would advice to buy a large, solid, enclosure with good ventilation. This would cost you around $200. But it will protect the hardware much better then a milk or vegi plastic case.
Just thoughts, I am NOT a professional electrical engineer. 

3773: <p>i went to configmyrig.com and selected the options to hit something close to 5mh.
here is a screenshot:</p>

<p><a href="http://s28.postimg.org/uayj19exp/Screen_Shot_2014_01_09_at_11_21_58_PM.png" rel="nofollow">http://s28.postimg.org/uayj19exp/Screen_Shot_2014_01_09_at_11_21_58_PM.png</a></p>

<p>i'll be scrypt mining at a multipool and the total that came up for the complete setup is about $5,000 seems like alot but let me know if you have any suggestions. What i'm wondering is how many PSU's would I will need and what kind is recommended? I'm thinking it would be a gold or platinum for the PSUs but i'm not sure how many and what kind would suit 6 Radeon R9 290x's. Also is the motherboard &amp; cpu selected good enough? I'll be using a milk carton for the rig instead of a case so i'll need to get a hold of a good one.</p>
 11862: <blockquote>
  <p>What i'm wondering is how many PSU's would I will need and what kind is recommended? </p>
</blockquote>

<p>I would recommend much higher PSU, at least 1000 Watt PSU for each two Radeon's R9 290x. This is based on some recommendations I found (<a href="http://www.tomshardware.co.uk/answers/id-1873375/power-supply-support-radeon-290s-290x.html" rel="nofollow">here</a> and <a href="http://www.tomshardware.co.uk/answers/id-1889129/power-supply-sapphire-280x.html" rel="nofollow">here</a>). I am 99.99% confident a single 750 Watt PSU will NOT be able to cover 6 GPUs of that power. </p>

<p>I also think the motherboard you selected can only take 3 cards, you need to double check. Even with 3 slots the cards may not have enough room between the slots, so you will need to use extension cables. The CPU is actually overpowered, I would select a low-power one. CPU will not be used for mining. Memory is not used as well. You will be covered with a 2-4GB stick to run the OS processes.</p>

<p>No one seem to be bothered with a case. For that much price of a hardware you don't want much dust to come in. Or any morning coffee spilt on your expensive hardware... I would advice to buy a large, solid, enclosure with good ventilation. This would cost you around $200. But it will protect the hardware much better then a milk or vegi plastic case.</p>

<p>Just thoughts, I am NOT a professional electrical engineer. </p>
