I don't know of any 54mm G size motors.
G motors run in the 24mm to 29mm range.
as for plans? Check out Jim Zs website and upscale something from there. Or if your into scale rockets check out Peter Always "Rockets Of The World" and scale to fit your desired size.
The Launch Pad has several plan packs in the Mid Power range.
So many different ways to go.
You can get alot of ideas from reading old threads on this forum and when you get an idea and have any specific questions we are glad to help.
I am currently scratch building a Nike Hercules and am posting the build in the Mid Power forum here under "need Herc ideas"
WELCOME to TRF
