Calculate what is more profitable for you. I would also buy 1 Corsair power supply because it is very reliable.
https://www.corsair.com/eu/en/Categories/Products/Power-Supply-Units/hxi-series-2017-config/p/CP-9020139-EU
And I sold your power supply if it was from AeroCool and so on.
I agree.You can never go wrong with Corsair.I also recommend the HX or RM series,HX Platinum or RM Gold,I have both of them Rm 1000 Gold and HX 1200 Platinum,they are running since the end of 2016 and powering up everything I throw to them.They will handle 4 Vega cards really easy without problems,a 750 Watt PSU is a sure thing that it will ruin itself or your cards with the passing of just a bit of time.