A NPPL would get you your licence quicker and cheaper than a PPL, but only because you potentially fly less hours to licence issue. To get say 100 hours in would of course cost pretty much the same by either route.
A NPPL then a PPL would certainly cost you more in the long run.
If, as you suggest, you may want night/IMC ratings in the future you would be best served by going straight for a PPL from the start in my view.
Good luck with the training whatever route you chose
