Looking a buying a field tile machine

Not sure best place to post this question. Any body been around a Koehring 600 wheel trencher. Looking at some trenchers to install 4 inch to 12 inch tile on our own farms. I have looked at some T600 vermeer trenches too. I don't have a big enough tractor to pull a plow so I need a trencher of some kind.

Looking a buying a field tile machine