What type of enclosure do I need?

u need to look in ur sub's manual, it should tell u the best recommended size, yes you should use screws and glue, dont be afraid to go crazy with glue. after you've bulit the box use caulking to all inside corners to ensure it's airtight. let it dry for a day, then put in sub, play sub and listen for air leak, if there is one fill it. thats for sealed box, ported, wel has a port so it's not airtight.