what kind of system should i use and what brand is the best.

what kind of shot would it be safe to run with a rebuilt rotory?

 

Im no expert but as far a who I would say NOS. Plus to be safer get a wet shot system. Let me get you a link: http://www.fc3s.org/
Use the menu on the left for wet / dry NOS system install. They make it seem easy. What aother mods are you planning.

 

Nitrous System makes much nicer kits than NOS-

But you really dont need to squeze a Turbo rotary- Maybe a very small 20-25 shot to cool things down if you live in a hot climate-
Your really asking for trouble, because its going to be very hard to get the thing in tune.