Drilling/overflow for 40 breeder

I'd definitely drill it!

Glass-holes.com has a real nice low profile kit available.

 

run it up to AC&C and have Andrew do it...i think it's like $10..call and confirm price though

 

What is the return of the pump? I'd recommend an overflow that can handle at least 500 GPH if not something around 800 that way you can crank the return pump up some and turn over the water a little faster. I am still working on my overflow, surface skimming, and return pump rate to get the best of all of them for my tank. Dialing in an overflow tanks some time to play with it. You may also want to look up the Bean Animal Overflow so you get a feel for how to plumb it later on. I'd have atleast 2 overflow drains that run to the sump that way you don't get so much gurgling. If you want to see an example of what NOT to do, let me know you can come see my tank lol