The color band's a great idea. On my boat, though, the mizzen is shorter. I just use the short stick at the back of the boat. I had some sitka spruce left over from another boat. If I didn't have that, I'd be picking through the 2x6 (non-sitka) spruce pile at Lowe's. Poplar is cheap around here, and light, too. It's a great choice, too. Hirlonde is correct-- the loads aren't as demanding as a boom. (Your sheet should attach to the sail, not the sprit.) Epoxy+varnish or just varnish, plus a chafing leather. I've seen wraps of twine used instead of leather, too.