[What oil is best and what does everyone use?]

Pretty much as heading states. What's the best or most common used. I've read on other forms and google as well the others range anywhere from none synthetic conventional oil to full all out race full synthetic. What's your thoughts and play nice.  lol 

[Curious about interchangeable parts maintenance questions]

So I got my cbr a little over a month ago and was curious on what all swingarms fit from other bikes also curious about the options of forks I could use. Then the dummy I bought the bike from tried to do his own breaks and messed up. So before I get started on these items. I wanted to know what other rims (since one is bent also not my fault) swing arms and forks fit on it. Then there's the brake leading sequence. I assume farthest from lever first and work my way in.