That's a completely opinion based answer. Everyone has their specific choices. Personally I run a basic oil for the initial break in and heat cycling, then change it to Amsoil full synthetic.
I agree with who gives a 6. The brand of the oil is personal preference, but the drill is the same. Use regular oil for break in and switch to a full synthetic afterwards. The transmission can go full synthetic from day one. The weight requirements are different for the transmission, but I have used several different ones with good results. I am still a fan of good old Honda 75/80W in the red bottle. As they use to use in the 250R 2 stroke transmissions. Another good add-in is a zinc additive if your oil (most don't) doesn't have it in the oil already. Keeps the cams and lifters alive. Eastwood has it. Good Luck.
I personally run nothing but Redline oils. After seeing how they coat and stick to the parts on the transmission side I haven't turned back. Gotta love the fact it looks like you ground up a smurf.