The UK is not the place for tuning any Jazz, however the Modified car brigade should be able to advise about a huge £'sssssssssss conversion with VETEC engine gearbox.
Tuning firms in USA thrive as they do in Aus
Try Spoon and other Japanese sites.
After you spend your £'s on a Jazz you may as well buy well used CRX or Civic then convert at your leisure, alternsatively if you like a risk import a car already converted