I'd raid the parts bin.
Dual disc front with progressive springs would be mandatory. Also that cool tubular fork brace you can buy for not much money is a nice addition.
Some Krauser bags and a seat with a passenger pillion would be nice too.
I'd be compelled to toss the stock sweeper type gauges with a digital computer setup like the Trailtech Vapor (speedo, tach, engine temp at the plug, mileage based service reminders, etc.) because of its low power draw and cool factor.
maybe some frame bracing too.
Kick those Bings to the curb for some Mikunis and never look back.
I'm just thinking of functional things that will make it better in traffic (stop, go, turn).
That bike is already all kinds of cool. Just make it better at being a rider.
"Ducati 900SS. It's not really a sportbike, it's your rosso clad mistress that has no qualms acting like a whore when you ride her. A cougar that takes her time, and knows how to push all your buttons." -Dilligaf