This feature is default available in Odoo V8, you need to install website_quote module first.
Lets create one Quotation Templates with "Suggested Product",
Navigate to : Sales>Configuration>Quotation Templates
We use this template into Sales Quotation,
Send it to customer via "Send By Email", so customer will open that quotation via portal,
Customer impress!!, They are ready to purchase :).
Customer will click "Add To Card" button to add this product into the quotation and write some notes.
Next Door Of Opportunity
It will auto update whole quotation with "Suggested Products"
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