Question on 72 gallon tank and biomaster

I have a 72 gallon 48x20x20 planted tank, there is going to be heavy bio load as I will be keeping discus. My plan was to run a boiomaster 350 and 600. However the 600 is noticeably louder then the 350 even though the spec shows the difference is only 50 gph more. Would it make sense to just use two 350s? from the sound of it, the current 350 is almost silent so running two would still be a huge decrease in the filter noise. I spoke to oase thinking my 600 was defective but they said it's normal and the 600 has a larger motor.