Congratulations on both your new unit and your pending retirement!
We use two twin fitted sheets on the bottom and a king for the top when we make our bed up. That seems to work well and makes it easy to leave the fitted sheets on during the day if we want.
You may want to grab the crowd sourced owners manual for the 24.1:
http://www.thorforums.com/forums/f17...ists-2488.html