Inspired by the question "Why is Luke's cybernetic hand superior to the one Anakin receives?" I got to wondering why Anakin and Luke were fitted with cybernetic hands. With such advanced cloning technology available it would seem to make more sense to fast grow custom limbs and organs as necessary, rather than to outfit people with cybernetics. If the answer is that cybernetics are vastly superior to organic organs why don't more people have elective surgery to "upgrade" themselves?
Ther's some ethic, legal and safety concern to Cloning a human body for replacement part:
Excerpt from Cybernetics Wookieepedia article
Cloning was expensive and, given the horrors of the Clone Wars, illegal on most planets after the era. Some limited regeneration of limbs was considered acceptable but there were medical dangers involved with a science that had, for obvious reasons, not seen much development in later decades after the Clone Wars. For the majority of galactic citizens, cybernetic replacements were the cheap, effective, legal, and safe solution to unfortunate and severe physical injuries.
As for why more people don't have elective surgery to "upgrade" themselves, it look like there was some side effects :
For those willing to make the sacrifice of flesh and expense, the body could be "upgraded" to allow for additional skills and abilities. Some were very innocuous, the Shepherd chip issued to military service members for instance. Others involved modifying the limbs and internal systems of the potential patient. As with everything in the galaxy, this came at a potential price, in credits and in the potential loss of self. Someone could easily go too far in attempting to be "more human than human."
Enhancements put more of a drain on the body's resources, and recipients frequently suffered debilitating physical or mental side effects.
There is no mention in-Universe that there existed technology to clone just human parts as opposed to alive beings, AFAIR.
I have a strong suspicion that a Jedi would have a minor Ethical quibble with growing a human being (even a clone) only to murder him to harvest a missing limb.
The cloning technology seem to be quite rare in the Starwars universe, and had a relatively long time to work. Growing an adult hand would have probably taken about 10 years, and who would want to wait for that length of time? It's possible that a cybernetic hand could have been used initially, and later it could be replaced by a cloned hand, but it seems to be rather unlikely.