The cases are functionally the same.
If you will have hot parts, like you are planning on triple graphics cards, then they will generate lots of heat.
You may need to keep the front door open while under load.
FWIW, I don't think X99 is the best platform for the gamer.
Yes, you will be able to run triple graphics cards.
But, the best haswell-E 6 and 8 core chips will not have the top clock rates that a overclocked i7-4790K will have.
Few games can make use of more than 2-3 cores.
There are Z97 based motherboards with 3 pcie X16 graphics slots.
Here is one:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157505
Such a Z97 motherboard will support next year's 14nm broadwell 4790K replacement.
Where is here?