While I agree on the GPU front, I don't agree on the CPU and Ram issue.
My Son-in-law runs FTB and several other high-end games and he is maxed out and needs more than he's got.
He has an MSI GD65 with 16GB Vengeance Ram with an i7 4770K CPU.
I'm also just about to build a rig based on an MSI Gamer board and my minimum is going to be an i7 4790K with 16GB Fury Ram.
Personally, I'd buy a case and build my own and add to it when I can afford it. If you really want a pre-built rig, I'd go the extra mile for the i7 rather than the i5 any day and add more Ram when you can.