Quite few fellows are running one of the three Amsoil 2-stroke oils. See the for sale thread at the bottom for my special and oil description.
Mix ratio depends on the oil, your conditions,your fuel/air mix.
Saber is the most common and protects the best. 30:1 is even pretty oil rich with Saber. 40:1 is fine for a well broken in engine. The oil is designed to work up to 100:1.
I have been using Dominator at about 30:1.