I completely feel you on this one brother. I had to go through the exact same route while getting 3 separate HDD cages for my Corsair 750D case which I use in a NAS build at home. The additional HDD cages were not available anywhere in India so had to import them from Corsair Taiwan at an inflated price. Without those cages the case holds 6 HDD's and with the additional cages one can expand it to a total of 14 HDDs.
I love this build of yours. Be sure to post another photo of it once you have put in the new components you will be adding in it. That Phanteks Enthoo Case at 7k is a steal... did you get it from Amazon?
We really need to create a Storage and NAS Thread separately here on TE for members to post photos of their NAS rigs at home, even ghetto setups!
You must post this NAS build of yours here as well:
[H]ard Forum Storage Showoff Thread