Bajan form the little I know about importing RIBs and boats in general from SAfrica, I think that GEMINI SA will not sell to you directly unless you buy the boat (any boat RIB or Zap) in SA and give an SA address. This means that your craft will not have a CE mark on it and it will not have a CE certificate which makes it illegal in Europe.
The reason they do that is like most boat builders in SA, Australia, New Zealand, USA, Brazil, Mexico etc they have an exclusive agency agreement with their agents in Europe and therefore not allowing others to import directly from the country of origin. Unless, of course, there is no agent in the country you want to import the boat and if an agent in Europe does not have exclusive European trade agreement with that builder.
The price you mentioned for a Zap Cat in the UK (I think) is quite expensive.
This more than the money we paid for the rescue 5 mtr RIB (WATERCRAFT) we have with engine, trailer etc and is Cat A.
Does this price include the engine and everything or just the boat? (race ready?)
In any case since there I cannot see that you have any alternative and GEMINI has the monopoly in racing (i.e. have to have a GEMINI Zap Cat, GEMINI prepared engine etc - for which I do NOT agree) so if you have made up your mind go 4 it