+1 on what p nut suggested.
So long as you are not concerned about weight, then some take off wheels are a good option. I got a pair of Bontrager Mustang wheels (from a Fisher Rig) for $100 and bought some Big Apples in the 2.3 flavor (for the cush). The only thing I found is that went I switch the wheels, I need to realign the brake calipers. The rotors are slightly shifted on the bontrager hubs compared to the king hubs that have my mountain tires. So if you can find a pair of stock Mary wheels, you'll probably have even less to worry about.
As for tires, just find some tires that are atleast wider than the rims. And you can find tires with light treads to slicks. Check some of the other threads
http://forums.mtbr.com/showthread.php?t=692563 about slick tires, some people have recommended Marathon Supremes, Fat Franks, and lightly treaded WTB Vulpine.