A gearbox remap may be better for you, considering the modest gains with an engine remap.
I have had my XFR remapped and pullies changed on SC. I have about 600hp and 700nm torque. This doesnt make the car undriveable, you just have to learn 'how' to drive this sort of power. Coincidentally it has improved my mpg. Combined is about 28mpg.
As for 'ride' my R is perfectly smooth. With the trick suspension it's comfortable just cruising around and sharpens itself up with enthusiastic driving. So you get the best of both worlds. If your NA has the trick suspension, then there will be no difference in ride between it and the R version.