The Danforth Hi-Tensile 5H, or the Danforth Standard S-920 are both adequate for the boat, and either should fit in the anchor locker.
Note: cheaper versions are available, but go with the good stuff if you want to stay put.
Good rule of thumb is one foot of chain for each foot of boat length. Adds enormously to the anchor digging in and staying there. We use 30-feet of 1/4" chain.
Three-strand nylon is the best bet for the anchor rode. 1/2" feels better in your hand than 3/8", but the smaller line is adequate. The 1/2" is recommended.
How much line? As much as you can fit in that anchor locker. Using the recommended 7:1 scope, with the bow about 5' above the water, you can anchor in 15-ft of water (at high tide) with a 150-ft anchor rode. Might be fine for that secluded creek you want to anchor in, but doesn't work if you lose power in 25-ft of water (or deeper) and the wind is up.
(Note: We oversize on ground tackle. Primary anchor is a Delta 22# with 30-ft of chain and 600-ft of 1/2" 8-plait rode. Secondary anchor is a Danforth 12H with 6-ft of chain and 200-ft of 1/2" three-strand.
Agree with the annual wash and fabric-softener treatment of the line. You can also rinse the line in the anchor locker. It has a dedicated drain tube to the bilge, so will collect in the forward bilge while in the water and likely the aft bilge if on a trailer. Easy to pump out.
Brian