Recommendations wanted for return bulkhead size for 30 gallon reef

[OpTiCz]

I'm in the process of building out my tank, which is 100cm x 35cm x 35cm.
I've installed the Eshopps Eclipse M overflow which is rated up to 800 gph.
I haven't picked up the sump yet, but will probably go with Eshopps RS-75.

Question is should I go with a single return line, say 3/4" or go with two, one at each end of the tank since it's a bit longer. What pump would you recommend if I split into two return bulk heads?

I'm coming from a biocube from several years ago, so sizing the proper return lines, pump, and sump is a bit new to me. Any help is greatly appreciated!

 

[RobZilla04]

30g will be fine with a single return line. Standard 3/4" will suffice to get you more than enough turn over provided you have an adequate pump.

Go with a DC pump so you can adjust the flow rate and run at less than 100%.

 

[Even Further]

I have a 38 gallon tank with a single over the top return, 3/4" pipe. It's more than enough.