Unless you are prepared to alter the jetting then Don't do any airbox mods, these things run lean standard to satisfy the emission laws, here is a link to what you should do to the carbs
http://www.motorradna.com/STOCKCARBMODS.HTM
I would suggest that you do this first then remove the snorkel, the bike will run a lot better with the carb mods.
After that you will need to change the muffler
After that you will need to change the header pipes
After that you will need to re-configure the airbox
After that you will need to have the Ignition box modified (to cut at 8100RPM not the 7100 they do as standard)
After that you will need to use the JE piston (lighter with more compression)
After that you will need to have the head gas flowed and a new cam
you will now have a bike which frightens you every tie you ride it
After that you are getting really serious !!! but I know how to do it