are you sure it's stronger springs you want, as I think I have the same problem with my 999s 04, it's fine when I seat on it but under hard braking it dives and uses up all the suspension travel,
more progressive springs will stop this and keep the ride height right, not stronger,
but I'm new to ducatis so any one with more experience and have fixed this is better than me. I understand the basics but havn't fix it.
ps I ant no light weight