So far I have an S&M ATF frame and forks for a 24" build. I know it's a freestyle frame and not a race frame, but it's a start.
I am looking at the Profile 19mm spline drive setup with 175 arms, but that isn't set in stone.
I did the track on my 29 XC racebike, and it was very fun. I don't know if it a "pump" track or not. Still learning here.