First, Please don't think having a more Efficient PSU will mean its a better PSU. Also most people who do get higher wattage is because of when the fan will turn on and all. 650 would be great for you even lower
550 G2 by EVGA which is a great psu made by leadex.
If you want more 650 P2 Same company and made by same company
A good quality unit will put out its rated wattage