I think you list makes sense for the most part. The Shannon is more expensive for a reason as far as I know though. I think it is a better built boat than a Bayfield especially for the southern route. You don't say where you are as that will have some bearing on the boats available. There is a steel Freya in San Francisco for sale. Rafiki in Hawaii. PSC 37 or Valiant are excellent choices. Pretorien shouldn't be hard to find and many have been offshore. Not sure of the Morgan.
Living aboard in Victoria Harbour