Sweeeet Build/Guide Bowlinra!!! 
 
Definitely will be an excellent reference for our Team and thank-you for putting it together for us! 

excellent write up Bowlinra
here are some pics of mine
watercooled in a Lian  Li PCA77 (EOL and has been replaced by the PCA 77F which doesn´t allow for the PSU to go in the top)

 
caseless with Noctua NH U9DO A3

 
and a dual setup with the Noctua NH U12DO A3

 
on the Noctuas I used their NH T1, don´t remember what i used on the waterblocks

you can add the mod i use on the 2P :


 
and the solution implemented on the Urlauber 2P

I thought they made server racks with multiple server trays in them, so you could run anywhere from 2 to 16 servers?
 
Do they make a smaller version of a server rack that can maybe hold 4 or so server trays?

In my area space is limited. So If I were to do a 4p build it would have to go in a case and be verticle. So the water cooler option would probably be the best for me. But then I'd need a new case to fit such a beast. We need to compile a list of any cases that will fit these monster boards with little to no modification if possible.
 
Very nice job so far bowlinra.
 
@NerdGZ, what kind of themps do the stock Phenom coolers give you?
Also @ Barbarossa, what water blocks are you using on your board?
And one final side note, Operon 6128 8 core CPU's are currently going for $165 or so on fleabay. For those of us that are wanting to do this on a faily tight budget. And yes I realize that budget and 4p machine don't go together so well.

@zophar 40ºCelsius with a 20mm 800rpm splitted over the heatsinks memory and with a 80mm fan on the bare metal behind hdd connectors.
This solution is noisy aprox 3600 rpm fans from the 2 Phenom II X4/x& are spinning.
Note to add to the post these Opteron CPU dies at 70ºC and over 54 -55ºC the CPU autoprotects them and does a shutdown/reboot.
I have seen one at 50ºC but after removing the cooler fans and do a clean i was at this temperature.
 

This deffinately needs to moved to the Help and Guides section. Great work.

NerdGZ
you can add the mod i use on the 2P : and the solution implemented on the Urlauber 2P

 
NerdGZ, I'll be glad to add it, Could you add some word explaining what you did, why and how for example.. It's not clear how and what you did from the pics, maybe because I'm not familiar with the stock version of the Urlauber 2P.

zophar
We need to compile a list of any cases that will fit these monster boards with little to no modification if possible. 

I have might have some more information, but most of it posted, just not organized well for cases information. I've mounted my to a board and will be adding the write up after some vacation.
 

zophar 
Also @ Barbarossa, what water blocks are you using on your board?

I haven't looked into water setups at all, maybe Barbarossa  or someone else can work up a "How To" and some cost numbers.

NerdGZ
Note to add to the post these Opteron CPU dies at 70ºC and over 54 -55ºC the CPU autoprotects them and does a shutdown/reboot.

Could you post a reference link?
I certainly haven't heard this with the Opteron 6100 series, I understand they start down clocking at 70ºC. 
 
Also what kinda of PPD are you getting out of the 2P setup?