Rxquickshifter

Hi everyone Im new to the rotary scene so i need a bit of help.i just bought a 92 3rd gen rx7 from my friend who imported it from japan,a week later the engine got damaged and had to be rebuilt new seals etc because the octane in irish petrol is only 95, now that i have it i dont want to suffer the same faith,some of my friends say remapping the ecu is the way but others say thats rubbish and that i have to put in a pro boost formula with every tank of petrol to up the octane.im seriously stuck and it would be a great help if you guys could give me some advice please anyone?