Decided to drill my tank

[Easto]

I have a 75 Gal and I was going to set up a sump-less system.

After some thought I have decided that I should just use a sump, however my tank isn't drilled.

Which size hole saw should I use?

Which size bulkhead should I buy?

I am not sure what the most common/best sizes are.

I was thinking of doing very basic plumbing using braided nylon. I can always hard plumb things later when I upgrade to a bigger system