Will all mark 1 clio tailgates/boots fit my mark 1 clio rsi?
Answers:
Yes. The tailgate is an expensive item to tool up for - no manufacturer makes different ones for the same model of car without good reason.
The only issue will be that later Mk1 Clios had a high-level brake lamp just below the rear screen, but the earlier ones didn't. If your car has one, you need a tailgate that also has one, so that your car still complies with its Type Approval. If your car didn't have one, its up to you if you add one or not.
The only car I can think of that had different tailgates for different versions was the original Fiat Uno, before the 1998 facelift - the normal models had a normal pressed-steel tailgate, but the Turbo had a plastic tailgate with moulded-in spoiler above the rear screen.