just check there the original size it´s not like in cars that you can fit fatter tires you have to respect the original size the size´in both tires is 120/70/17 (58W) and on the back is 180/55/17 (73W) the thing you have to look on motorcycle tyres is the use you´re gonna give to them if you´re just gonna use youre bike for commuting then tires like michelin pilot sport will do if you drive in twisty roads then perhaps pilot power will do, or if you race pilot race are perfect...
the variations in tires have to do with the compounds they´re made harder tires will last longer, but have less grip,and do not have to get to temp. they´re great for touring, while softer tires have more grip but last a lot less, they´re great for \