You could enquire with
Falkland Performance (St.Monans) to see if they could do anything for you. I have exactly the same setup as you on my GR86 and one of the reasons I chose to go that way was that there was no requirement to remap.
Unfortunately, being a NA engine you'll likely not see the same sort of performance increases that you might with a Turbocharged engine - I seem to recall figures of around 10hp at the 'peak' output mentioned in a thread somewhere within this forum? You may feel smoother delivery and a more linear torque curve, but performance? Probably not so for everyday driving. I'm sure others with more 'tuning experience' can add to this thread better than I can ...