Jt- keep the lid as light and simple as possible. The guys with 2" car exhaust or Bavarians pipe make for nice light lids and developed from experience with heavy or unweildy lids- trying to handle a hot unbalanced lid with one hand and mopping or flipping food with the other isn't easy peasy. For your intake -since you are in New England, I would go up a size in ID and bring the valve up higher. I like this when I'm cooking in a snow storm and my UDS is in a snowdrift. Also, winter cooking at 20 below requires a little more air intake then our New mexico Brethren with a 110 degree day.
One other thought- food safe barrels doesn't mean unlined.