You can find insightful speculation about what such a society of nanoenhanced men might look like in John C. Wright's "Golden Age" trilogy. It is one of the most daring scenarios I've read, and raises many interesting questions about how to know whether you are still the same person in a world where any alteration you can imagine, physical or mental, is available to you. Unlike many science fiction books of similar nature (like "Altered Carbon", for instance) that try making everything dark, dirty, and depressing, these books display a refreshing optimism, which alone makes them worth reading.