You can buy a new hub and rotor if you want to run them dual disc. I sell the hubs for $250 so that gives you an idea on the additional cost. PM rotors are $350 each retail. I sell them for $300. $2300 for two wheels, two tires and both rotors is a screaming deal on PM stuff. Retail is around $3500 or so. Almost forgot, if you have ABS add $50 to the hub for the ABS bearing.
What's the tread depth like now on front and rear?
Not real good at all. When i listed the tire over a year ago the rear was brand new. They can still be rode for a bit but tires are in the near future. I would take 1000.00 and thats still a heck of a deal even if you have to buy tires.