The 7200 conventional frame is similar if not the same to the 7000.
7200s were also available as a "conservation" (what we have) and are a lot beefer construction.
7200s can be vacuum planters, but only the later vaccuum version can be updated to the Precision Planting equipment.
7200 row units can be set on 15" centers; 7000s are a little wider, and can only be set down to 18-20" spacing.
Good luck- there are lots of choices out there.