How to make an easy free classified

Hey everyone,
I need to make something similar to Classifieds! These are the functions I need:

1- People be able to post simple ads. This could be done by filling out a google form which is synched to a google spreadsheet (for instance with rental offers). The spreadsheet's columns can be "date - email - type of property - price - number of rooms"

2- The spreadsheet can be viewed by everyone EXCEPT I want people not be able to see each others emails. I want a mechanism so that they can send emails without knowing the receivers email so that he/she can reply or not reply!

3- I talked about google forms and spreadsheet because Classified templates are not free but these are so thought maybe there would be a way around paying for the template?

Do you guys think there is any way I can handle this problem for free?

Thanks