If you could take pictures of the control panel as well as the racks inside the dishwasher, this way I can see how the water is fed to the upper wash arm under the top rack.    A model number would be helpful too.

Whatever racks you need, besides Kenmore, a Whirlpool or KitchenAid dishwasher from the same period could have used the same type.

You're wise to keep the Ultra Wash.  They are excellent performers.

besides Kenmore, a Whirlpool or KitchenAid dishwasher from the same period could have used the same type.

The statement above is exactly why I wanted to know how the water was fed to the upper wash arm.  The statement above will not apply at all.  You will need to looks for racks with that pole or column in the middle of the bottom rack.  I venture to guess there may also be a short stubby version of this in the middle of the upper rack to supply water to the deflector on the top of the tub.  You could look for a used replacement rack that will fit either a Whirlpool or a Kenmore with that column or "nozzle" as I refer to it.  The Whirlpool version will be about an inch or so not as deep because of having to make "room" for the protruding in-the-door silverware rack.  The Kenmore version will have the space in the rack for the flatware basket as well as the "bull-nose" protrusion that makes the rack a little bit deeper at the front of it. And that little bit of depth can make a ot of difference in loading pattern and capacity.  And I don't blame you for wanting to keep that dishwasher until it falls apart.  We might want to help you start looking for a replacement, used similar model to have in reserve when that time comes.  As far as the differences between UltraWash I, II, & III, I don't think there's any real difference.  They all use the same basic Whirlpool PowerClean module design pump.  It might have something to do with whether water supply for the upper wash arm was fed through the "nozzle" like yours vs. being directly fed to the upper wash arm through a tube that went along the back of the dishwasher tub up to a tube that it connected to that went under the top rack.  Others here who know the intricate mechanical design difference might be able to contribute to this piece of the puzzle. 

Dave, I downloaded the user manual  Pots & Pans heats the water to 135 degrees in the prewash, main wash, and final rinse.  Normal, only heats the water in final rinse.  To have water heating for Normal or Light Wash, just keep the Pots & Pans cycle button pushed in and turn the selector cycle dial to Normal or Light places on the dial.