You could try Kage Baker's series-which-does-not-have-a-name-yet. The two books in it are called In the Garden of Iden and Sky Coyote. 'ees vurry fan-tas-teek.
I wouldn't classify either book as "science fiction", but they do deal with some of the same concepts. For example: both are based around the lives of technological immortals created by a futuristic company called Doctor Zeus (ha ha - Zeus - geddit?), which has developed a method of time travel. These immortals are all recruited out of diverse eras in the past, tinkered with, and sent out again to walk forward through time, stealing and hiding valuable resources, like animals, art, literature, and plants, for future generations to enjoy.
I know it sounds incredibly corny, but Kage Baker does amazing things with a theme that would otherwise be unbearable. The woman's a genius.
In the Garden of Iden deals with a cyborg named Mendoza, assigned as a botanist to Tudorean England. Sky Coyote follows - well, I wouldn't say her "mentor", but the operative who recruited her - but it follows him on one of his own assignments to save the culture of the Chumash Nation of northern California. Excellent stuff. Mwah.