you are not going to get any different results between testosterone esters... npp is a shorter ester so you are pinning more frequently... its easier to use the same type of ester to be on the same pinning schedule so i would go with test prop.. that way you can also run a shorter cycle... 8-10 weeks is just fine with shorter esters...
I prefer to keep the esters the same so if you run NPP, stick to test P. I actually prefer long esters though so instead, I would run test E with deca.