Plumbing Help !!!!

[scar_11]

I am going to drill my tank maybe tomorrow and I just want some advise from the experts.

I have 2.. inch and a half bulk head I was going to use for the overflow. one has a strainer that screws in. I was planning on using it in my over flow box That I have. The other I was planning on having a 90 in the tank turned up just about the water line incase my one line plugs.

I have 1... 3/4 inch with flexy house I was going to use this as my return line from the sump

Where should I mount the Over flow box and where should I mount the return line?
Should I get another 3/4 and have 2 return lines?

I have pictures of all my stuff I will post any advice would be great
Thanks

Overflow Box 6x6x6

Overflow box and bulkheads

Standard 90 gallon tank