Is there any equipment/Cybernetics or other mod to make a droid appear like a normal human, other then lots of synthskin?

Well replacing all its appendages with prosthetics...

Not in any of the books I know of.

I'd say maybe with some work you could get an already very humanoid droid looking OK from a distance and under heavy clothing, but nothing that would stand up to anything more than casual scrutiny unless it's a custom built infiltrator droid. The infiltrator droid would be pretty expensive and missing some cybernetics slots, needing a lot of stuff that would be superfluous on a normal droid (micro-motors for facial expression, a tongue and mouth, breathing, ability to fake eating or bleeding, etc)

Probably easier to make a human look like a droid.....after all they do it all the time in the movies.....