DIY dual overflow

[daplatapus]

Greetings and welcome to Canreef!
For photo sharing, it's best to open a photobucket account and use the "IMG" links then the pics are right in your post, people don't have to click the links to see the pics.
Right now your pic links aren't valid

As to your last question, you'd be better off using 4" filter socks if you can fit them in than using foam filters I think. Easier to clean and not so much traps for detritus.