I would appreciate any information on a one way trip for these cities. We don't want to do a needless loop, and waste a lot of time.

You don't specify how you want to do this trip.
Please specify so that I can help you better.

If you want to do it by yourself you can simply buy train tickets.

If you want to do it with a tour, I would recommend the
following tour:
http://www.affordabletours.com/Globus_T . .. .. . isure.html

We are not sure. We will be in Switzerland in July, and can fly out of Rome to get home. So we thought we would do Italy while we were there, but don't want to do one of those standard loop tours that start and end in Rome.

thanks for your input.

The tour that I mentioned only goes one way. Unfortunately, it goes from Rome to Milan. There are many other tours that are also one way. You might want to search here for other options:

http://www.affordabletours.com/