Best overflow plumbing for a reef ready 120

[smokinreefer]

Hey,

I'll be setting up a reef ready 120 tank that has 2 prebuilt overflows
and the standard 2 holes drilled on inside bottom of each overflow.

1 for drain and 1 smaller one for return in each overflow.

Would it be better to use both holes for the drain on each side?

I do not have a problem just plumbing the return over the top.
And I would prefer as quiet a drain as possible.

Please leave me your input!