+1000 on doing a search about oil!!!
But I will say, since I'm already posting anyways lol, and not that I wouldn't either, but oil is one of this things that promotes high brand loyalty, and what ever type of oil that a individual uses is what they think is best and that is what they will recommend. I use royal purple max cycle, it's just what I prefer, I've used the regular stuff in my cars for years with ridiculous good results, and am also very pleased with the results in the bike. IMHO what ever moto specific oil you choose, or oil that can be run with a wet clutch, wether it be full synthetic, synthetic blend, or pure dino you will be fine. However not all oils are the same and you might find you need to adjust the clutch, or other shifting issues depending on what you choose. But do a forum search and you will find all kinds of info on oils that members use as well as filters