Bulkhead/Pump Reco for Refugium

[jtown]

I'm building a refugium and I was wondering what you guys would suggest for the following setup:

 

29 main tank

10 gallon below tank refugium

Intend to build an internal overflow box in the 29 as well as drill a hole in the back of the tank for the line to the refugium. I plan on making an external (?) durso.

 

Here are my questions:

- What size hole should I drill in the back of the tank? 1"?

- How far down the back of the tank should I put the bulkhead/durso?

- What kind of pump or gph should I be shooting for? I've noticed the mag pumps are popular.

 

Thanks!