Good luck. Nauru is not a common destination for people heading through the South Pacific since it is a very unattractive island because of the mining and the anchorage is not very good there. Also you need a pretty big boat to be able to accomodate 6 or 8 guests and their gear. A final thought, going to Banaba is pretty much exactly to windward, so even though it is not so far in terms of distance it would be a fairly rugged trip. Sounds like you might need a good-sized powerboat for this.
Heading back to Lake Ontario for this summer. Relatively few stops along the way from Grenada. Martinique, Guadeloupe, St. Martin (must have something to do with the French food), then Bermuda, New England and up the Hudson/Erie Canal. We were going to go via Newfoundland and Labrador but June remembered that one of the kids is getting married this summer - details, details!