A 600 cc crotch rocket is simply a sport bike. Supersport/Superbike is 1000+ cc
Types of bikes is a whole different discussion and there are no well defined categoties since there are bikes that overlap two or more categories.
To address the original question, I think it's much more simpler to buy one from a local dealer. Or ask them to import one for you. The extra fees you pay are negligible.
I imported a 2015 Ducati Diavel Carbon in June 2017 through a personal contact from Canada. The guy in Canada did all the work on the canadian side, and a local dealer from Islamabad (Rypers) got all the customs clearance etc done. There are a few set rules for the customs and mostly it goes by precedent set by previously imported bikes. MSRP and model year are the key in determining factors. Again you can find out the exact duty pased on the VIN of the bike. Ask your local bike dealer and they should be able to tell you.