The best source of ships images is Atlantic Fleet Sales!
Over half of the links that I had posted on this page have vanished since I last did an update.
This person is not on online, but I have had several people tell me that they have good photos at a reasonable price:
Real War Photos American Civil War, World War II, Korea, Vietnam battle action 8x10 glossy photos taken by combat photographers.
Thousands of photos available.
For a full catalog, or a list of photos available for a particular ship or unit, send $5 to:
Real War Photos, PO Box 728, Hammond, IN 46324