First off the bearing doesn't mount into the flywheel, it goes into the back of the crankshaft. Should be no big deal reusing the old bearing. They don't usually wear out. If it did I would take it down to the parts store and tell them I wanted one just like it. Don't use the bushing. It will work but it's not what you want in there.
Have you looked at the new throwout yet? There are at least two different lengths of bearings. Some kits come with a different length and when you try to put it in you only end up with partial clutch throw.
