I have to questions for anybody who can help me out:

1. the bike i bought came with a 190 rear tires, i dunno what stock is but it seems bigger(biggest one able to fit the rim). if so, how would this affect the handling...sometimes when i take turns it feels like my back end is sliding out from under me.

2. what are the lights that go on the top corners of the headlights/where can i find those?

 

I believe 180 is stock, I dont feel any difference personally when I used either or. Some say a 180 handles better but I havent felt it. As for the lights, above your high beams is nothing, people will do the blinker conversion(I had it). You just have to drill out the plastic to fit a bulb with connector and wire to your turn signals. I used old turn signals and took the bulb and boot from the housing and drilled a hole a tad bit smaller then the boot. I think it looks pretty cool but when I got the bike painted the guy didnt re-install the blinkers since I put flush mounts.

 

190 rear tire is stock, you can fit up to a 200 on back. If your sliding out a bit its not the tire profile, its either worn or a crappy brand most likely. Pimpin answered the rest for yai think.