can i use a f4i or there others swingarms i can use and where can i get cool headlights and speedometer guages

 

pretty loaded question there.
you can use f4i gauges on your bike. you will need to splice and dice, and you will also need to get a mounting bracket like the ones i used to make. you can use other gauges, but i dont know much about them.
headlights?...as in HID, or you want a whole new front end?
swingarm: many/most... almost all other swingarms will require heavy modification to get on, as well as a new weld point for the dogbone/ shock.