you put the details of your frame into the boxes for make, date, model etc , then it brings up a list of all the forks that will fit and the bearings you need to fit them, just scroll down till you find Suzuki GSF600 2000.
it gives you the bearing sizes i have already said with their part No's in blue
top bearing = 25 - 48 - 13
bottom bearing = 30 - 48 - 12