A Deus Ex Machina Yamaha 400 cc bike with upside down forks, ohlins suspension and a keihin fcr-mx 39 pumper carb.
An air filter might not look as cool but the engine will certainly last longer.
Come on, a carbon fiber fender mated with a mechanical-linked rear drum brake. There's a reason why people don't put caviar on cheez its. I'm not a huge fan of the dual, slider piston front brakes either, especially considering that the front forks probably came off a sport bike with proper brakes.
Below was a Yamaha 250 that I found outside of Atlantis Motors in Silverlake. The bike looks sharp, like the kind of bike I'd want to motor about town.