You will need 1500 watts. However, AMD highly recommend a true 8 pin PCI-e connector instead of a 6+2 pin PCI-e connector, as an 8 pin connector is the most stable, in terms of current flow and electrical power charge. I highly recommend Corsair's new AX1500i. That has true 8 pin connectors, so you can power those cards no problem.
do not forget ...your cpu can reach 220W power consumption max at full load and can cause overheat problem...
BUT YOUR ARE SMART to choosen the asus motherboard...because of the accuracy of reading the temp directly from the bios, so you can see the real temp by the asus II software
give a try whit the AX 1500I psu like SR-71 BLACKBIRD said , but which pc case you choosen?
because with the rig you have ..maybe is better to have a separate psu, one for the mobo and other like the 1500W psu
for the gpus only??? what do you think?
1. Can I use two fan controllers in a build/computer?
2. I've heard that in some countries you are only allowed to pull a specific amount of watts, from the mains, before the circuit breakers break the current. I live in the UK will it be fine to use a 1500w PSU or will it not work?
3. In some countries there is not a steady power supply, will I get a steady power in the UK supply using a 1500w psu?
All EU countries have very stable power grids to sustain your system, that includes the UK. It is only if you do some very serious stuff with your system, which includes Bitcoin mining, is when you start emptying your own wallet.