I had the same symptoms with the full-floaters on mine - once they get too worn they're f8cked. I ended up putting them on a 750 Monster because it wasn't likely to be doing too much 100+ mph stopping!!
I got a good deal on a pair of new Brembos, but use EBC floaters on my race bike (£220 a pair)
Normal steel discs will fit but you will notice the difference
Paul