There is a couple different Goex types, but the Goex superfine sporting powder is what you want to look for. As for granulation size, you have Fg that is for the big bore rifles/muskets, cannons, FFg 45 caliber on up FFFg 32 caliber to 54 caliber (some use this in bigger) FFFFg priming powder for flintlocks.
My primary is FFg for my 45 calibers up to my 12 gauge.