I'm building a gaming pc and I got some tech questions about compatibility, plus I need to know if I'm doing any major pc building mistakes as this is my first time building a pc. I decided to go for ddr4 but I don't know the exact reasons, I just think they're better. So I have to get a z170 chipset motherboard and a cpu compatible with ddr4 plus ddr4 memories.

This is my full DDR3 build along with the peripherals;

Razer deathadder mouse
Razer blackwidow keyboard
Samsung S24D390HL monitor
CASE CORSAIR CARBIDE SERIES 100R SILENT EDITION
Be Quiet Pure Power L8 700W
Samsung 850 evo 250 gb
MSI r9 390
Kingston HyperX Fury Black 8gb ddr3
Gigabyte z97x gaming 5
Intel core i5 4690k

This is my DDR4 build;

Razer deathadder mouse
Razer blackwidow keyboard
Samsung S24D390HL monitor
CASE CORSAIR CARBIDE SERIES 100R SILENT EDITION
Be Quiet Pure Power L8 700W
Samsung 850 evo 250 gb
MSI r9 390
Intel core i5 6600
Kingston HyperX Fury 8gb ddr4
Gigabyte z170x gaming

The price difference is pretty narrow with the ddr4 build slightly more expensive.

Question#2; This might sound stupid but do I add up the power each component uses to see what psu I have to buy? Because the r9 390 gpu eats up a ton of watts(~430 at max performance) I don't know if the 700 watt psu is enough. I don't know if the rest of the components eat up that much but I gues the cpu is kinda close to that too at max performance. If I exceed the watts my psu offers what happens? Things burn down or my pc just restarts?