99 dodge dually to single?
 

I have a 1999 dodge 3500 diesel dually 4x4. I want to put a round bale feeding bed on it and take off the outside duals for the winter and snow. What should I do to make the back match up with the front? Should I get new rims and tires which I am willing to do and change rims and tires out? I would like to make it a dually again for summer work. Any suggestions?