I know I am late, but still.
It would be more than enough if you will upgrade to 32GBs of RAM and a better videocard.
Both of the suggested power supplies by SR-71 Blackbird are really good. But it would make more sense to spend around $10 more for the Gold-rated power supply for your safety.
But it would not be certainly enough for SLI or CrossfireX.
If you are thinking about a SLI or CrossfireX upgrade in the near future, this : https://pcpartpicker.com/list/JwjH8d would be the safest bet.