NS PRO 105t shafts & 712AP2

What are you asking? Shafts are definitely important for ballooning, but what are you asking about distance?

I can't get the distance out of my 6 5 and 4 irons

But  I love my 7 8 9 P should I go with different 

Shafts for the 6 5 and 4Irons

Yes, definitely see your local pro or fitter to put you on Trackman or something to figure out why you are lacking distance with your long irons. Shafts definitely can make a huge impact. 

I was fitted for PXI 5.5 it will give me same feel as ns 105t with more distance and lower launch