Drilling a tank

[C&C]

I have a 130 gallon glass aquarium and thinking about getting it drilled.

How far from the corner should I have it drilled and what size hole? I am planning two over flows (one in each corner).

What about returns, right now I am not planning on drilling it for returns, but am open to other ideas.

I live in Fredericton NB, anybody know where a good place to get a tank drilled?

What size pippe should I use for the overflows?