Do not include too many details.. You have been asked to something preliminary but complete. So focus on the most important companies (top 10) giving details on the 4-5 most relevant aspects. In my opinion, you should look at:
It's important to realize how "big" the target is"
2) Relevant business
Assuming that you are focusing on an industry, it still matters knowing from which segment the money comes from
3) EBITDA Marging
At a preliminary stage, this is crucial. You do not want to buy something with margins lot smaller than yours
4) Relevant strategic information
Whether they are restructuring, growing, cutting costs, investing
5) Cash and debt
They influence how much you will pay for the target.
Hope this helps!