How to make mailmerge with communication fields?

Hello,

I would like some advice about a development I have to do in sageCRM 7.1 sp2.

The objective is to see under the companies:

  • The equipments that we sold.
  • The contract they have on it
  • The interventions made during the contract
  • Print Intervention forms

I have added a new primary entity "Equipment" that depends on Company.

On that entity I have the reference to the equipment sold to the customer: link to products, serial number, sold date, end of warranty, ...

The main problem is about the forms I have to print. My first idea was to use communications under my new entity. It is the best way to have the intervention in the calendar. But we can't create templates with the communication fields (or I don't know how to do it...).

So the second idea is to create a new entity depending on my entity "equipment". I can create a second entity as explained in Jeff's post

https://community.sagecrm.com/partner_community/b/hints_tips_and_tricks/archive/2010/06/08/how-to-create-a-secondary-entity-for-a-new-custom-primary-entity.aspx#comments

But can we create templates on new secondary entities?

What is the best way to implement this solution?

Thanks for your help.

Jerome