If you are just gaming, the maximus vii formula and the 4790k is enough. It will save you some bucks too.
The maximus vii formula can only sli 2 nvidia graphics cards. If you are going to use more than two nvidia cards then you will want to go with the rampage board.
But since you are only running 2 nvidia cards, My choice would be the Formula vii and 4790k.
If you put two gtx 980's in the formula vii, you will have one power house of a gaming pc.
You don't have to water cool the formula vii, but the option is there if you have a water loop.
I'm predicting the gtx 980 will cost $749.99. So $749.99 x 2 = $1,500.00