A handful of Space Marines like the ones suggested wouldn't be worth a new thread for it, and I kind of doubt anyone wants to run an army of them.

As for the reading as human thing, as long as it read as partly human if the cybernetics were obvious, I don't think there'd be a problem. A lot of people in the Imperium have cybernetic limbs or organs and the Techpriests of Mars are always tinkering with more.
If they weren't obvious in any way however, there'd be no real way to know and it'd probably be bad...