What Neu for 5s in 8T?

[kevin23]

I just picked up a race roller 8T and would like to get a neu 1515 for it.
I have 2 4s and 2 5s tp 5000mah packs.
I would like to run 5s but could run 4s also.
I am looking for nitro like speed with good runtime,I only run it on a offroad track.
I have an 8b with a 1512 2.5 on 5s and love it,I am looking for similar power and runtime as this setup if possible.
Thanks always for the info,
Kevin

I was looking at a 1515 1y just not sure if it would be the best choice.