Airdale said:
Diamond Star DA-20 with glass cockpit
A 2 seater with glass? Was this a custom, field approved install, or was it a DA40?
In any case, do the training in what you can afford.
If you want to learn the G1000, and you have the money for it, then use that plane. The plane flies the same, the panel is just different. As is the radio and audio panel setup.
You only really look at the panel a small percentage of the time in an ideal world. I've found in real life though, that most of my students look at the panel way too much. May as well have a panel where you can get the information in a much faster way.
Spend a few hours with the King G1000 course, or with the instructor of they know the system well.
If you want something different to fly in, that is better to train in, use something other than a 172. You'll learn more flying a modern 2 seat plane, that'll give you good flying habits. Then if you choose to for some reason, you can fly a skychicken.
The easiest way to decide what to fly is figure out what your goal is, and use the plane that is the fastest way to get there.