Nick
Go to 1/2" Anchor rode 3 Strand. From your post it sound like you don't have a Windlass.
I would geta round laundry basket, cut a piece of plywood to fit inside on the bottom, attach either the center from an old wire spool or mount two 2x4's (1' in length) spaced far enough apart to let you coil your rope around the inside of the basket with no tangles.
When going deep water wreck fishing I have a 600' line stored in my basket and utilize that without a problem.
Use a minimum of 10 ft of chain on the line.
Hope it helps