Hi Andy,
Some of the tropical woods I have seen pictures of carvings in are cocobolo (rosewood), spanish cedar, bocote, and goncalo aves. All of these except the cedar are hardwoods and may be more difficult to carve than the usual basswood, butternut white pine, and cedar generally used here in the U.S.
Good whittlin, Cliff
Charles City, Iowa
http://cliffordparker.tripod.com