The Atlantic 55 is a very close sister to the Atlantic 57. The interior layout is the same. The additional length in the 57 is in the bows, with small changes to the foretriangle sail area.
There were 5 A55s built in South Africa, and one in the US. To date, 11 A57s have been built in the US and Chile. Occasionally an A55 comes up for sale. Check our brokerage page and yachtworld listings