Thanks a lot.
I did some research and came up with these. Prices in Singapore dollars. So I would need a 1000W for this?
Seasonic X-1050 80+ Gold/Full Modular $299
Seasonic X-1250 $369
Seasonic platinum 1000w $325
Corsair RM1000 $269
Again this is for IDEAL power usage which may only be a 1-5% advantage so keep in mind if your annual power cost for 400-500 watts is less than the difference between a 500W power supply and a 1000 watt power supply you may be spending money you don't have to. But who doesn't need an awesome 1000W PSU
So if you pay $0.25 per Kwh (.25*.48*24*365) = $1051.20 per year
Platinum 1000 92.54% = $1135.94
The 1050 is 91.04% = $1154.65
The 1250 is 91.40% = $1149.89
The corsair is 91.34% = $1150.64
For comparison A bronze rated corsair CX500 for $59.99 USD would run about 82.82% = $1269.25
Again. Feel free to correct anything that may be wrong here.