Okay I am not wedded to the idea of an Ironclad and can see that perhaps an improve Alabama type ship might be something that would give the Hawaiians greater range and flexibility. I could not see it having more than two of these ships and the rest would be smaller.
The Royal Navy built two classes of wooden gunvessels between 1859-1867, the Philomel and the Cormorant. Many of the ships apparently were sold off within ten years. They ranged between 570-877 tons and had crews ranging from 60-90 men. Smaller than the Alabama, and bearing five guns they would probably work fine as a means of 'cutting their teeth'.