Thank you for the helpThere were 3 generations of the Integra. First Gen (86-89), Second Gen (90-93) and Third Gen (94-01). In Japan, there was no RSX, and they were also called the Integra. Technically in Japan, there were 4 generations which was the RSX. For US, only 3 gens.
For your second question, really depends on the specific parts. Some parts were missing and/or added throughout the generations for OBD compliance, trims, etc. Some parts are the same, some aren't.