Don't be ridiculus, all "cafe racers" must have a hoop, checkerboard, knee indents, clubman bars and no fenders. Everybody knows that!!! Don't forget to put on pod filters or velocity stacks and have an open triangle. There is also no need to worry about upgrading suspension, brakes, tires or wheels as long as you put on shorter shocks and drop the front end.
Just kidding, don't be that guy that just wants to make a formulaic cafe racer. Mods need to be done with purpose to improve the performance of the bike, not just make it an art piece unless that is your intent. If you are into it strictly for the aesthetics, then you will really need to pay attention to all the details and be meticulous in your choices of parts, materiels and construction.
I am really a form follows function kind of guy and go for as much performance as my budget and skill set will allow and tend to lean towards handling and suspension rather than horsepower.