My only caveat is that you didn't use a "redundant" power server case. Everything else appears OK, too. As for the case, that PSU will do, but here too you may want to have a spare PSU. Now, make darn sure all of this is well cooled, which a server case would have provided and have amble room as well. Just check out server cases to get a feel of what I'm suggesting here. I do like 100% you use a true server mtrbd..
Please let me know what you think...
I am ordering the adaptec card to run raid 5 with 4 hdd (ordered 5 in case one dies)