Getting tank drilled this weekend...any final suggestions?

[Michael]

I'm getting a 48X18X20 tank drilled this weekend and am looking for any last minute tips or suggestions you can give me.
-1 corner overflow. Drain hole will be on the side (can't put it in the bottom due to stand setup). I figure a 1.5" hole should be big enough.

-draining to 50 gallon sump with mag12 and a Klaes Junior skimmer. Return will be a mag12 pump.
-Refugium will be added later.

--Any other suggestions with regards to getting any other holes drilled? I only want to have to take it to the store once to get all necessary holes drilled.

Thanks.

Michael