You need at least 400' of chain backed by 3/4" nylon (to support the weight of chain). Don't forget the 600' of line on a spool for the shore line. Of course if you are anchoring in the south sound, then 6' of vinyl coated chain and 100' of 1/2" nylon will do the job.

I would go with gray for the locker so it will blend in with the sky.