I have 9k to spend, and I figure, since there will be 4 graphics cards and LGA2011, I'd need liquid cooling. My friend says you'd need it for 3 graphics cards. I have not decided upon a case yet, so I need to know some good ones.
With that system then you will need a monolithic case, when you say 9k is that $,£ or Euros ?
Do you really need 4 x 7970 GPUs? What resolutions will you be running?
The only case i can think of for your needs, and yes you will definately need to watercool all those GPUs to keep them in check, is this case..
Silverstone Temjin TJ11B-W Full Tower Extended E-ATX Aluminum, Black with Side Window w/o PSU http://www.scan.co.uk/products/silverstone-tj11b-w-full...
Your friend is wrong that you 'need' liquid cooling for 3+ graphics cards- you certainly don't if you have good airflow. However, it seems you have a lot of research and sticky reading ahead of you. Please read through the watercooling link in my signature below.