In terms of being able to send text and/or graphic material with the order... Yes, Zencart can do this.

However, you are looking for a feature that is sometimes called "conditional attributes" - where the value inserted in one field influences the display (or content) of other fields.

Right now, ZC cannot do the latter, but we are all hoping that the next release (1.4) will have this capability.

There are various modules available that cope with group pricing, and there are a number of people who could assist with custom code if necessary.