intercoolers and turbo size for nissan

Hi I am new to this site and I am looking forward to getting some useful info and hopefully one day will get a chance to meet up with some of the sites users

I have a terrano 1993 model running a 5speed manual g/box the engine number is a TD27T and I am looking at putting in an intercooler and up grading the turbo and running at a higher boost when off roading in the sand ect but I am having no joy in finding out what the 4X has in it's current form as to the size of the turbo ect

just hoping that someone here has done this and what the results have been like and what other mods have been done or have to be done like do I need to be looking at bigger injectors fuel pump or rising fuel pressure reg better pistons and decompression plate and if I need to be looking at a piggy back computor or chipping it to help out also a larger throttle body and pod filter as well ect so any help or advice on this would be great and what else would be great was if I could get names and addressess for reliable companies who can help out

I live in W.A in the deep dark south west corner