Hi cain . to answer your questions

1. Glow plugs that work best with that fuel range

20% nitro you would use a medium plug , #6

2. Pipes that work best with engine types for buggy and truggy

We found the following work well LRP 2063 , HN 2062 , SH 2060 , HN 2047 in that order

3. Which type works best for buggy versus truggy and why?

Truggy we found 2063 works because of the torque the pipe gives , HN 2047 for buggy .. its smoother in bottom ..

4. Do all the engines include extra glow plugs?

No plugs included

hope this helps !

Cheers MM