wats a good glow plug for my buggy's sirio .26 engine?

that varies with the weather conditions and the fuel you use.

ok, im using white lightning fuel and since its summer..obviously warm to hot weather

a cold or medium plug. Mcoy are some of te best out there.

Are you running 20% or 30% nitro? If you run 30% you need a colder plug. I am using the mccoy #8 plugs in my engine running 20% nitro. Also make sure it doesn't take a turbo plug.