I'd rather the RM-650 or Antec HCG 520M than the VS 650
Its usually recommended that you use 2 x 4GB instead of 1 x 8GB to keep the Memory Controller happy - increased speed.
I'm glad I got a 120GB OD drive - I get a lot of other stuff on it other than the OS - printer and router software etc - that won't let you do a custom install on it.
What Operating System?
Otherwise, I'd be happy with what you've listed
1.Hard disk space required by win 8.1 is 16 GB (32-bit) or 20 GB (64-bit) so i think 60 gb is far more than enough
2. i am using 1x8gb so that i can upgrade later on with 1 more 8 gb ram
3. case i have not decided yet!!